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//////////////////////////////////////////////////////////////////////
// LibFile: screws.scad
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// Functions and modules for creating metric (ISO) and English (UTS) standard screws and nuts.
// Included is a function for calculating the standard dimensions of screws including the
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// tolerance values that are required to make screws mate properly when they are formed
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// precisely. If you can fabricate objects accurately then the modeled screws will mate
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// with standard hardware without the need to introduce extra gaps for clearance.
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// Includes:
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// include <BOSL2/std.scad>
// include <BOSL2/screws.scad>
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// FileGroup: Threaded Parts
// FileSummary: ISO (metric) and UTS screws and nuts.
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//////////////////////////////////////////////////////////////////////
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include < structs.scad >
include < threading.scad >
include < screw_drive.scad >
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// Section: Screw Parameters
// This modules in this file create standard ISO (metric) and UTS (English) threaded screws.
// The {{screw()}} and {{nut()}} modules produce
// screws and nuts that comply with the relevant ISO and ASME standards,
// including tolerances for screw fit. You can also create screws with
// various head types and drive types that should match standard hardware.
// Subsection: Screw Naming
// You can specify screws using a string that names the screw.
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// For ISO (metric) screws the name has the form: "M`<size>`x`<pitch>`,`<length>`,
// so "M6x1,10" specifies a 6mm diameter screw with a thread pitch of 1mm and length of 10mm.
// You can omit the pitch or length, e.g. "M6x1", or "M6,10", or just "M6".
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// .
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// For UTS (English) screws the name has the form `<size>`-`<threadcount>`,`<length>`, e.g.
// "#8-32,1/2", or "1/4-20,1". The units are in inches, including the length. Size can be a
// number from 0 to 12 with or without a leading # to specify a screw gauge size, or any other
// value to specify a diameter in inches, either as a float or a fraction, so "0.5-13" and
// "1/2-13" are equivalent. To force interpretation of the value as inches add '' (two
// single-quotes) to the end, e.g. "1''-4" is a one inch screw and "1-80" is a very small
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// 1-gauge screw. The pitch is specified using a thread count, the number of threads per inch.
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// As with the ISO screws, you can omit the pitch or length and specify "#6-32", "#6,3/4", or simply #6.
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// Subsection: Standard Screw Pitch
// If you omit the pitch when specifying a screw or nut then the library supplies a standard screw pitch based
// on the screw diameter. For each screw diameter, multiple standard pitches are possible.
// The available thread pitch types are different for ISO and UTS:
// .
// | ISO | UTS |
// | -------- | -------- |
// | "coarse" | "coarse" or "UNC" |
// | "fine" | "fine" or "UNF" |
// | "extrafine" or "extra fine" | "extrafine", "extra fine", or "UNEF" |
// | "superfine" or "super fine" | |
// | "none" | "none" |
// .
// The default pitch selection is "coarse". Note that this selection is case insensitive.
// To set the pitch using these pitch strings you use the `thread=` argument to the modules.
// You cannot incorporate a named pitch into the thread name. The finer pitch categories
// are defined only for larger screw diameters. You can also use the `thread=` argument to
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// directly specify a pitch, so `thread=2` produces a thread pitch of 2mm. Setting the
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// pitch to zero produces an unthreaded screws, the same as setting it to "none". Specifying
// a numeric value this way overrides a value given in the name.
// Subsection: Screw Heads
// By default screws do not have heads.
// You can request a screw head using `head=` parameter to specify the desired head type. If you want the
// head to have a recess for driving the screw you must also specify a drive type using `drive=`.
// The table below lists the head options. Only some combinations of head and drive
// type are supported. Different sized flat heads exist for the same screw type.
// Sometimes this depends on the type of recess. If you specify "flat" then the size will be chosen
// appropriately for the recess you specify.
// .
// The `drive=` argument can be set to "none", "hex", "slot",
// "phillips", "ph0" to "ph4" (for phillips of the specified size), "torx" or
// "t<size>" (for Torx at a specified size, e.g. "t20"). If you have no head but still
// give a drive type you will get a set screw. The table below lists all of the head types and
// shows which drive type is compatible with each head types. Different head types work in ISO and UTS,
// as marked in the first column.
// .
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// |ISO|UTS|Head | Drive |
// |---|---|--------------- | ----------------------------|
// |X|X|"none" | hex, torx|
// |X|X|"hex" | *none*|
// |X|X|"socket" | hex, torx|
// |X|X|"button" | hex, torx|
// |X|X|"flat" | slot, phillips, hex, torx|
// | |X|"round" | slot, phillips |
// | |X|"fillister" | slot, phillips |
// | |X|"flat small" | slot, phillips|
// | |X|"flat large" | hex, torx |
// | |X|"flat undercut" | slot, phillips |
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// |X|X|"pan" | slot, phillips, torx (ISO only) |
// |X| |"cheese" | slot, phillips, torx |
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// .
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// The drive size is specified appropriately for the drive type: drive number for phillips or torx,
// and recess width in mm or inches (as appropriate) for hex. Drive size is determined automatically
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// from the screw size, but by passing the `drive_size=` argument you can override the default, or
// in cases where no default exists you can specify it.
// Subsection: Tolerance
// Without tolerance requirements, screws would not fit together. The screw standards specify a
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// nominal size, but the tolerance determines a range of allowed sizes based on that nominal size.
// So for example, an M10 screw with the default tolerance has an outside (major) diameter between 9.74 mm and 9.97 mm.
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// The library will use the center point in the allowed range and create a screw with a diameter of 9.86 mm.
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// A M10 nut at the default tolerance has a major diameter (which is the inside diameter) between 10 mm and 10.4 mm.
// Shrinking the major diameter of a screw makes the screw loose. Shrinking the major diameter of a nut, on the other hand,
// makes the hole smaller and hence makes the nut tighter. For this reason, we need a difference tolerance
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// for a screw than for a nut. Screw tolerances shrink the diameter to make the screw looser whereas nut tolerances
// increase the diameter to make the nut looser. Screws modeled using this library will have dimensions consistent with the
// standards they are based on, so that they will interface properly if fabricated by an accurate method. The ISO and UTS
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// systems use different tolerance designations.
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// .
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// For UTS screw threads the tolerance is one of "1A", "2A" or "3A", in
// order of increasing tightness. The default tolerance is "2A", which
// is the general standard for manufactured bolts.
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// .
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// For UTS nut threads, the tolerance is one of "1B", "2B" or "3B", in
// order of increasing tightness. The default tolerance is "2B", which
// is the general standard for manufactured nuts.
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// .
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// The ISO tolerances are more complicated. For both screws and nuts the ISO tolerance has the form of a number
// and letter. The letter specifies the "fundamental deviation", also called the "tolerance position", the gap
// from the nominal size. The number specifies the allowed range (variability) of the thread heights. For
// screws, the letter must be "e", "f", "g", or "h", where "e" is the loosest and "h" means no gap. The number
// for a screw tolerance must be a value from 3-9 for crest diameter and one of 4, 6, or 8 for pitch diameter.
// A tolerance "6g" specifies both pitch and crest diameter to be the same, but they can be different, with a
// tolerance like "5g6g" specifies a pitch diameter tolerance of "5g" and a crest diameter tolerance of "6g".
// Smaller numbers give a tighter tolerance. The default ISO screw tolerance is "6g".
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// .
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// For ISO nuts the letters specifying the fundamental deviation are upper case and must be "G" or "H" where "G"
// is loose and "H" means no gap. The number specifying the variability must range from 4-8. An allowed (loose)
// nut tolerance is "7G". The default ISO tolerance is "6H".
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// Section: Making Screws
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/*
http : //mdmetric.com/thddata.htm#idx
Seems to show JIS has same nominal thread as others
https : //www.nbk1560.com/~/media/Images/en/Product%20Site/en_technical/11_ISO%20General%20Purpose%20Metric%20Screw%20Threads.ashx?la=en
Various ISO standards here : https : //www.fasteners.eu/standards/ISO/4026/
Torx values : https : //www.stanleyengineeredfastening.com/-/media/web/sef/resources/docs/other/socket_screw_tech_manual_1.ashx
* /
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// Module: screw()
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// Usage:
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// screw([name], [head], [drive], [thread=], [drive_size=], [length=|l=], [shank=], [oversize=], [tolerance=], [$slop=], [spec=], [details=], [anchor=], [anchor_head=], [orient=], [spin=]) [ATTACHMENTS];
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// Description:
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// Create a screw. See [screw parameters](#section-screw-parameters) for details on the parameters that define a screw.
// The tolerance determines the dimensions of the screw
// based on ISO and ASME standards. Screws fabricated at those dimensions will mate properly with standard hardware.
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// The $slop argument creates an extra gap to account for printing overextrusion. It defaults to 0.
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// .
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// You can generate a screw specification from {{screw_info()}}, possibly create a modified version, and pass that in rather than giving the parameters.
// .
// If you specify `internal=true` then you are creating a mask to make a threaded hole. Such threading masks follow
// the **nut** tolerance.
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// Arguments:
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// name = screw specification, e.g. "M5x1" or "#8-32". See [screw naming](#subsection-screw-naming).
// head = head type. See [screw heads](#subsection-screw-heads) Default: none
// drive = drive type. See [screw heads](#subsection-screw-heads) Default: none
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// ---
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// thread = thread type or specification. See [screw pitch](#subsection-standard-screw-pitch). Default: "coarse"
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// drive_size = size of drive recess to override computed value
// oversize = amount to increase screw diameter for clearance holes. Default: 0
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// spec = screw specification from `screw_info()`. If you specify this you can omit all the preceeding parameters.
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// length = length of screw (in mm)
// shank = length of unthreaded portion of screw (in mm). Default: 0
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// internal = set to true to create a screw mask for clearance holes (with no threads) or for threaded holes. If true, the driver recess will not be created on headed screws. Default: false
// counterbore = set to length of counterbore, or true to make a counterbore equal to head height. Default: no counterbore
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// details = toggle some details in rendering. Default: false
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// tolerance = screw tolerance. Determines actual screw thread geometry based on nominal sizing. See [tolerance](#subsection-tolerance). Default is "2A" for UTS and "6g" for ISO. If `internal=true` then default is "2B" for UTS and 6H for ISO.
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// $slop = add extra gap to account for printer overextrusion. Default: 0
// anchor = Translate so anchor point on the shaft is at origin (0,0,0). See [anchor](attachments.scad#subsection-anchor). Default: `BOTTOM`
// anchor_head = Translate so anchor point on the head is at origin (0,0,0). See [anchor](attachments.scad#subsection-anchor).
// spin = Rotate this many degrees around the Z axis after anchor. See [spin](attachments.scad#subsection-spin). Default: `0`
// orient = Vector to rotate top towards, after spin. See [orient](attachments.scad#subsection-orient). Default: `UP`
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// Example(Med): Selected UTS (English) screws
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// $fn=32;
// xdistribute(spacing=8){
// screw("#6", length=12);
// screw("#6-32", head="button", drive="torx",length=12);
// screw("#6-32,3/4", head="hex");
// screw("#6", thread="fine", head="fillister",length=12, drive="phillips");
// screw("#6", head="flat small",length=12,drive="slot");
// screw("#6-32", head="flat large", length=12, drive="torx");
// screw("#6-32", head="flat undercut",length=12);
// screw("#6-24", head="socket",length=12); // Non-standard threading
// screw("#6-32", drive="hex", drive_size=1.5, length=12);
// }
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// Example(Med): A few examples of ISO (metric) screws
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// $fn=32;
// xdistribute(spacing=8){
// screw("M3", head="flat small",length=12);
// screw("M3", head="button",drive="torx",length=12);
// screw("M3", head="pan", drive="phillips",length=12);
// screw("M3x1", head="pan", drive="slot",length=12); // Non-standard threading!
// screw("M3", head="flat large",length=12);
// screw("M3", thread="none", head="flat", drive="hex",length=12); // No threads
// screw("M3", head="socket",length=12);
// screw("M5", head="hex", length=12);
// }
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// Example(Med): Demonstration of all head types for UTS screws (using pitch zero for fast preview)
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// xdistribute(spacing=15){
// ydistribute(spacing=15){
// screw("1/4", thread=0,length=8, anchor=TOP, head="none", drive="hex");
// screw("1/4", thread=0,length=8, anchor=TOP, head="none", drive="torx");
// screw("1/4", thread=0,length=8, anchor=TOP, head="none");
// }
// screw("1/4", thread=0, length=8, anchor=TOP, head="hex");
// ydistribute(spacing=15){
// screw("1/4", thread=0,length=8, anchor=TOP, head="socket", drive="hex");
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// screw("1/4", thread=0,length=8, anchor=TOP, head="socket", drive="torx");
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// screw("1/4", thread=0,length=8, anchor=TOP, head="socket");
// }
// ydistribute(spacing=15){
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// screw("1/4", thread=0,length=8, anchor=TOP, head="socket ribbed", drive="hex",$fn=32);
// screw("1/4", thread=0,length=8, anchor=TOP, head="socket ribbed", drive="torx",$fn=32);
// screw("1/4", thread=0,length=8, anchor=TOP, head="socket ribbed",$fn=24);
// }
// ydistribute(spacing=15){
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// screw("1/4", thread=0,length=8, anchor=TOP, head="button", drive="hex");
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// screw("1/4", thread=0,length=8, anchor=TOP, head="button", drive="torx");
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// screw("1/4", thread=0,length=8, anchor=TOP, head="button");
// }
// ydistribute(spacing=15){
// screw("1/4", thread=0,length=8, anchor=TOP, head="round", drive="slot");
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// screw("1/4", thread=0,length=8, anchor=TOP, head="round", drive="phillips");
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// screw("1/4", thread=0,length=8, anchor=TOP, head="round");
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// }
// ydistribute(spacing=15){
// screw("1/4", thread=0,length=8, anchor=TOP, head="pan", drive="slot");
// screw("1/4", thread=0,length=8, anchor=TOP, head="pan", drive="phillips");
// screw("1/4", thread=0,length=8, anchor=TOP, head="pan");
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// }
// ydistribute(spacing=15){
// screw("1/4", thread=0,length=8, anchor=TOP, head="fillister", drive="slot");
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// screw("1/4", thread=0,length=8, anchor=TOP, head="fillister", drive="phillips");
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// screw("1/4", thread=0,length=8, anchor=TOP, head="fillister");
// }
// ydistribute(spacing=15){
// screw("1/4", thread=0,length=8, anchor=TOP, head="flat", drive="slot");
// screw("1/4", thread=0,length=8, anchor=TOP, head="flat", drive="phillips");
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// screw("1/4", thread=0,length=8, anchor=TOP, head="flat", drive="hex");
// screw("1/4", thread=0,length=8, anchor=TOP, head="flat", drive="torx");
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// screw("1/4", thread=0,length=8, anchor=TOP, head="flat large");
// screw("1/4", thread=0,length=8, anchor=TOP, head="flat small");
// }
// ydistribute(spacing=15){
// screw("1/4", thread=0,length=8, anchor=TOP, head="flat undercut", drive="slot");
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// screw("1/4", thread=0,length=8, anchor=TOP, head="flat undercut", drive="phillips");
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// screw("1/4", thread=0,length=8, anchor=TOP, head="flat undercut");
// }
// }
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// Example(Med): Demonstration of all head types for metric screws without threading.
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// xdistribute(spacing=15){
// ydistribute(spacing=15){
// screw("M6x0", length=8, anchor=TOP, head="none", drive="hex");
// screw("M6x0", length=8, anchor=TOP, head="none", drive="torx");
// screw("M6x0", length=8, anchor=TOP);
// }
// screw("M6x0", length=8, anchor=TOP, head="hex");
// ydistribute(spacing=15){
// screw("M6x0", length=8, anchor=TOP, head="socket", drive="hex");
// screw("M6x0", length=8, anchor=TOP, head="socket", drive="torx");
// screw("M6x0", length=8, anchor=TOP, head="socket");
// }
// ydistribute(spacing=15){
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// screw("M6x0", length=8, anchor=TOP, head="socket ribbed", drive="hex", $fn=32);
// screw("M6x0", length=8, anchor=TOP, head="socket ribbed", drive="torx", $fn=32);
// screw("M6x0", length=8, anchor=TOP, head="socket ribbed", $fn=32);
// }
// ydistribute(spacing=15){
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// screw("M6x0", length=8, anchor=TOP, head="pan", drive="slot");
// screw("M6x0", length=8, anchor=TOP, head="pan", drive="phillips");
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// screw("M6x0", length=8, anchor=TOP, head="pan", drive="torx");
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// screw("M6x0", length=8, anchor=TOP, head="pan");
// screw("M6x0", length=8, anchor=TOP, head="pan flat");
// }
// ydistribute(spacing=15){
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// screw("M6x0", length=8, anchor=TOP, head="button", drive="hex");
// screw("M6x0", length=8, anchor=TOP, head="button", drive="torx");
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// screw("M6x0", length=8, anchor=TOP, head="button");
// }
// ydistribute(spacing=15){
// screw("M6x0", length=8, anchor=TOP, head="cheese", drive="slot");
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// screw("M6x0", length=8, anchor=TOP, head="cheese", drive="phillips");
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// screw("M6x0", length=8, anchor=TOP, head="cheese", drive="torx");
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// screw("M6x0", length=8, anchor=TOP, head="cheese");
// }
// ydistribute(spacing=15){
// screw("M6x0", length=8, anchor=TOP, head="flat", drive="phillips");
// screw("M6x0", length=8, anchor=TOP, head="flat", drive="slot");
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// screw("M6x0", length=8, anchor=TOP, head="flat", drive="hex");
// screw("M6x0", length=8, anchor=TOP, head="flat", drive="torx");
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// screw("M6x0", length=8, anchor=TOP, head="flat small");
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// screw("M6x0", length=8, anchor=TOP, head="flat large");
// }
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// }
// Example: The three different English (UTS) screw tolerances
// module label(val)
// {
// difference(){
// children();
// yflip()linear_extrude(height=.35) text(val,valign="center",halign="center",size=8);
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// }
// }
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// $fn=64;
// xdistribute(spacing=15){
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// label("1") screw("1/4-20,5/8", head="hex",orient=DOWN,atype="head", anchor=TOP,tolerance="1A"); // Loose
// label("2") screw("1/4-20,5/8", head="hex",orient=DOWN,atype="head", anchor=TOP,tolerance="2A"); // Standard
// label("3") screw("1/4-20,5/8", head="hex",orient=DOWN,atype="head", anchor=TOP,tolerance="3A"); // Tight
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// }
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// Example(2D): This example shows the gap between nut and bolt at the loosest tolerance for UTS. This gap is what enables the parts to mesh without binding and is part of the definition for standard metal hardware. Note that this gap is part of the standard definition for the metal hardware, not the 3D printing adjustment provided by the $slop parameter.
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$ slop = 0 ;
$fn = 32 ;
projection ( cut = true ) xrot ( - 90 ) {
screw ( "1/4-20,1/4" , head = "hex" , orient = UP , anchor = BOTTOM , tolerance = "1A" ) ;
down ( INCH * 1 / 20 * 2.145 ) nut ( "1/4-20" , thickness = 8 , diameter = 0.5 * INCH , tolerance = "1B" ) ;
}
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function screw ( name , head = "none" , drive , thread = "coarse" , drive_size , oversize = 0 , spec , length , l , shank = 0 , tolerance = undef , details = true , anchor = undef , anchor_head = undef , spin = 0 , orient = UP ) = no_function ( "screw" ) ;
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module screw ( name , head = "none" , drive , thread = "coarse" , drive_size , oversize = 0 , internal = false ,
spec , length , l , shank = 0 , tolerance = undef , details = true , shank_diam , counterbore = 0 ,
atype = "shaft" , anchor = BOTTOM , spin = 0 , orient = UP )
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{
spec = _validate_screw_spec (
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is_def ( spec ) ? spec
: screw_info ( name , head , drive , thread = thread , drive_size = drive_size , oversize = oversize ) ) ;
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head = struct_val ( spec , "head" ) ;
pitch = struct_val ( spec , "pitch" ) ;
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nominal_diam = struct_val ( spec , "diameter" ) ;
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threadspec = pitch = = 0 || is_undef ( pitch ) ? undef : thread_specification ( spec , internal = internal , tolerance = tolerance ) ;
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d_major = pitch = = 0 ? nominal_diam : mean ( struct_val ( threadspec , "d_major" ) ) ;
shank_diam = first_defined ( [ u_add ( shank_diam , oversize ) , d_major ] ) ;
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headless = head = = "none" ;
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dummy1 = assert ( in_list ( atype , [ "shaft" , "head" ] ) ) ;
dummy2 = assert ( atype = = "shaft" || ! headless , "You cannot anchor headless screws with atype=\"head\"" ) ;
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screwlen = one_defined ( [ l , length ] , "l,length" , dflt = undef ) ;
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length = first_defined ( [ screwlen , struct_val ( spec , "length" ) ] ) ;
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dummy3 = assert ( all_positive ( length ) , "Must specify positive length" ) ;
sides = max ( 12 , segs ( nominal_diam / 2 ) ) ;
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unthreaded = is_undef ( pitch ) || pitch = = 0 ? length : shank ;
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threaded = u_add ( length , - unthreaded ) ;
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head_height = headless || starts_with ( head , "flat" ) ? 0 : struct_val ( spec , "head_height" ) ;
head_diam = struct_val ( spec , "head_size" ) ;
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flat_height = ! starts_with ( head , "flat" ) ? undef
: let ( given_height = struct_val ( spec , "head_height" ) )
is_def ( given_height ) && given_height > 0 ? given_height
: ( head_diam - d_major ) / 2 / tan ( struct_val ( spec , "head_angle" ) / 2 ) ;
eps_top = headless ? 0
: starts_with ( head , "flat" ) ? - flat_height + 0.01
: . 01 ;
eps_bot = . 01 ;
eps_unthreaded = unthreaded > 0 ? eps_top : 0 ;
eps_threaded = unthreaded > 0 ? eps_bot : eps_top ;
echo ( eps_thread = eps_threaded , lengthfinal = length + eps_threaded , unth = unthreaded , th = threaded ) ;
dummy4 = assert ( is_undef ( flat_height ) || flat_height < length , str ( "Length of screw (" , length , ") is shorter than the flat head height (" , flat_height , ")" ) ) ;
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attach_size = atype = = "head" && head = = "hex" ? [ head_diam , head_diam * 2 / sqrt ( 3 ) , head_height ] : undef ;
attach_d = atype = = "shaft" ? d_major
: head = = "hex" ? undef
: head_diam ;
attach_l = atype = = "shaft" ? length
: head = = "hex" ? undef
: head_height ;
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attachable (
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size = attach_size ,
d = attach_d ,
l = attach_l ,
orient = orient ,
anchor = anchor ,
spin = spin )
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{
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up ( atype = = "head" ? - head_height / 2 : length / 2 )
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difference ( ) {
union ( ) {
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screw_head ( spec , details , counterbore = counterbore , flat_height = flat_height ) ;
if ( unthreaded > 0 )
up ( eps_unthreaded ) cyl ( d = shank_diam , h = unthreaded + eps_unthreaded , anchor = TOP , $fn = sides ) ;
if ( threaded > 0 ) {
down ( unthreaded - eps_threaded )
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threaded_rod ( [ mean ( struct_val ( threadspec , "d_minor" ) ) ,
mean ( struct_val ( threadspec , "d_pitch" ) ) ,
d_major ] ,
pitch = struct_val ( threadspec , "pitch" ) ,
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l = threaded + eps_threaded , left_handed = false , internal = internal ,
bevel1 = details , bevel2 = details && starts_with ( head , "flat" ) && ! headless && ! internal ,
$fn = sides , anchor = TOP ) ;
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}
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}
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if ( ! internal ) _driver ( spec ) ;
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}
children ( ) ;
}
}
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module _driver ( spec )
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{
drive = struct_val ( spec , "drive" ) ;
if ( is_def ( drive ) && drive ! = "none" ) {
echo ( inside_drive = drive ) ;
head = struct_val ( spec , "head" ) ;
diameter = struct_val ( spec , "diameter" ) ;
drive_size = struct_val ( spec , "drive_size" ) ;
drive_width = struct_val ( spec , "drive_width" ) ;
drive_diameter = struct_val ( spec , "drive_diameter" ) ;
drive_depth = first_defined ( [ struct_val ( spec , "drive_depth" ) , . 7 * diameter ] ) ; // Note hack for unspecified depth
head_top = starts_with ( head , "flat" ) || head = = "none" ? 0 :
struct_val ( spec , "head_height" ) ;
up ( head_top - drive_depth ) {
// recess should be positioned with its bottom center at (0,0) and the correct recess depth given above
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if ( drive = = "phillips" ) phillips_mask ( drive_size , anchor = BOTTOM ) ;
if ( drive = = "torx" ) torx_mask ( size = drive_size , l = drive_depth + 1 , center = false ) ;
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if ( drive = = "hex" ) hex_drive_mask ( drive_size , drive_depth + 1 , anchor = BOT ) ;
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if ( drive = = "slot" ) cuboid ( [ 2 * struct_val ( spec , "head_size" ) , drive_width , drive_depth + 1 ] , anchor = BOTTOM ) ;
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}
}
}
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function _ISO_thread_tolerance ( diameter , pitch , internal = false , tolerance = undef ) =
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let (
P = pitch ,
H = P * sqrt ( 3 ) / 2 ,
tolerance = first_defined ( [ tolerance , internal ? "6H" : "6g" ] ) ,
pdiam = diameter - 2 * 3 / 8 * H , // nominal pitch diameter
mindiam = diameter - 2 * 5 / 8 * H , // nominal minimum diameter
EI = [ // Fundamental deviations for nut thread
[ "G" , 15 + 11 * P ] ,
[ "H" , 0 ] , // Standard practice
] ,
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es = [ // Fundamental deviations for bolt thread
[ "e" , - ( 50 + 11 * P ) ] , // Exceptions if P<=0.45mm
[ "f" , - ( 30 + 11 * P ) ] ,
[ "g" , - ( 15 + 11 * P ) ] , // Standard practice
[ "h" , 0 ] // Standard practice for tight fit
] ,
T_d6 = 180 * pow ( P , 2 / 3 ) - 3.15 / sqrt ( P ) ,
T_d = [ // Crest diameter tolerance for major diameter of bolt thread
[ 4 , 0.63 * T_d6 ] ,
[ 6 , T_d6 ] ,
[ 8 , 1.6 * T_d6 ]
] ,
T_D1_6 = 0.2 < = P && P < = 0.8 ? 433 * P - 190 * pow ( P , 1.22 ) :
P > . 8 ? 230 * pow ( P , 0.7 ) : undef ,
T_D1 = [ // Crest diameter tolerance for minor diameter of nut thread
[ 4 , 0.63 * T_D1_6 ] ,
[ 5 , 0.8 * T_D1_6 ] ,
[ 6 , T_D1_6 ] ,
[ 7 , 1.25 * T_D1_6 ] ,
[ 8 , 1.6 * T_D1_6 ]
] ,
rangepts = [ 0.99 , 1.4 , 2.8 , 5.6 , 11.2 , 22.4 , 45 , 90 , 180 , 300 ] ,
d_ind = floor ( lookup ( diameter , hstack ( rangepts , count ( len ( rangepts ) ) ) ) ) ,
avgd = sqrt ( rangepts [ d_ind ] * rangepts [ d_ind + 1 ] ) ,
T_d2_6 = 90 * pow ( P , 0.4 ) * pow ( avgd , 0.1 ) ,
T_d2 = [ // Pitch diameter tolerance for bolt thread
[ 3 , 0.5 * T_d2_6 ] ,
[ 4 , 0.63 * T_d2_6 ] ,
[ 5 , 0.8 * T_d2_6 ] ,
[ 6 , T_d2_6 ] ,
[ 7 , 1.25 * T_d2_6 ] ,
[ 8 , 1.6 * T_d2_6 ] ,
[ 9 , 2 * T_d2_6 ] ,
] ,
T_D2 = [ // Tolerance for pitch diameter of nut thread
[ 4 , 0.85 * T_d2_6 ] ,
[ 5 , 1.06 * T_d2_6 ] ,
[ 6 , 1.32 * T_d2_6 ] ,
[ 7 , 1.7 * T_d2_6 ] ,
[ 8 , 2.12 * T_d2_6 ]
] ,
internal = is_def ( internal ) ? internal : tolerance [ 1 ] ! = downcase ( tolerance [ 1 ] ) ,
internalok = ! internal || (
len ( tolerance ) = = 2 && str_find ( "GH" , tolerance [ 1 ] ) ! = undef && str_find ( "45678" , tolerance [ 0 ] ) ! = undef ) ,
tol_str = str ( tolerance , tolerance ) ,
externalok = internal || (
( len ( tolerance ) = = 2 || len ( tolerance ) = = 4 )
&& str_find ( "efgh" , tol_str [ 1 ] ) ! = undef
&& str_find ( "efgh" , tol_str [ 3 ] ) ! = undef
&& str_find ( "3456789" , tol_str [ 0 ] ) ! = undef
&& str_find ( "468" , tol_str [ 2 ] ) ! = undef )
)
assert ( internalok , str ( "Invalid internal thread tolerance, " , tolerance , ". Must have form <digit><letter>" ) )
assert ( externalok , str ( "invalid external thread tolerance, " , tolerance , ". Must have form <digit><letter> or <digit><letter><digit><letter>" ) )
let (
tol_num_pitch = parse_num ( tol_str [ 0 ] ) ,
tol_num_crest = parse_num ( tol_str [ 2 ] ) ,
tol_letter = tol_str [ 1 ]
)
assert ( tol_letter = = tol_str [ 3 ] , str ( "Invalid tolerance, " , tolerance , ". Cannot mix different letters" ) )
internal ?
let ( // Nut case
//a=echo("nut", tol_letter, tol_num_pitch, tol_num_crest),
fdev = struct_val ( EI , tol_letter ) / 1000 ,
Tdval = struct_val ( T_D1 , tol_num_crest ) / 1000 ,
df = echo ( T_D1 = T_D1 ) ,
Td2val = struct_val ( T_D2 , tol_num_pitch ) / 1000 ,
//fe= echo("nut",P,fdev=fdev, Tdval=Tdval, Td2val=Td2val),
bot = [ diameter + fdev , diameter + fdev + Td2val + H / 6 ] ,
xdiam = [ mindiam + fdev , mindiam + fdev + Tdval ] ,
pitchdiam = [ pdiam + fdev , pdiam + fdev + Td2val ]
)
[ [ "pitch" , P ] , [ "d_minor" , xdiam ] , [ "d_pitch" , pitchdiam ] , [ "d_major" , bot ] , [ "basic" , [ mindiam , pdiam , diameter ] ] ]
:
let ( // Bolt case
//a=echo("bolt"),
fdev = struct_val ( es , tol_letter ) / 1000 ,
Tdval = struct_val ( T_d , tol_num_crest ) / 1000 ,
Td2val = struct_val ( T_d2 , tol_num_pitch ) / 1000 ,
mintrunc = P / 8 ,
d1 = diameter - 5 * H / 4 ,
maxtrunc = H / 4 - mintrunc * ( 1 - cos ( 60 - acos ( 1 - Td2val / 4 / mintrunc ) ) ) + Td2val / 2 ,
//cc=echo("bolt",P,fdev=fdev, Tdval=Tdval, Td2val=Td2val),
bot = [ diameter - 2 * H + 2 * mintrunc + fdev , diameter - 2 * H + 2 * maxtrunc + fdev ] ,
xdiam = [ diameter + fdev , diameter + fdev - Tdval ] ,
pitchdiam = [ pdiam + fdev , pdiam + fdev - Td2val ]
)
[ [ "pitch" , P ] , [ "d_major" , xdiam ] , [ "d_pitch" , pitchdiam ] , [ "d_minor" , bot ] , [ "basic" , [ mindiam , pdiam , diameter ] ] ] ;
function _UTS_thread_tolerance ( diam , pitch , internal = false , tolerance = undef ) =
let (
d = diam / INCH , // diameter in inches
P = pitch / INCH , // pitch in inches
H = P * sqrt ( 3 ) / 2 ,
tolerance = first_defined ( [ tolerance , internal ? "2B" : "2A" ] ) ,
tolOK = in_list ( tolerance , [ "1A" , "1B" , "2A" , "2B" , "3A" , "3B" ] ) ,
internal = tolerance [ 1 ] = = "B"
)
assert ( tolOK , str ( "Tolerance was " , tolerance , ". Must be one of 1A, 2A, 3A, 1B, 2B, 3B" ) )
let (
LE = 9 * P , // length of engagement. Is this right?
pitchtol_2A = 0.0015 * pow ( d , 1 / 3 ) + 0.0015 * sqrt ( LE ) + 0.015 * pow ( P , 2 / 3 ) ,
pitchtol_table = [
[ "1A" , 1.500 * pitchtol_2A ] ,
[ "2A" , pitchtol_2A ] ,
[ "3A" , 0.750 * pitchtol_2A ] ,
[ "1B" , 1.950 * pitchtol_2A ] ,
[ "2B" , 1.300 * pitchtol_2A ] ,
[ "3B" , 0.975 * pitchtol_2A ]
] ,
pitchtol = struct_val ( pitchtol_table , tolerance ) ,
allowance = tolerance = = "1A" || tolerance = = "2A" ? 0.3 * pitchtol_2A : 0 ,
majortol = tolerance = = "1A" ? 0.090 * pow ( P , 2 / 3 ) :
tolerance = = "2A" || tolerance = = "3A" ? 0.060 * pow ( P , 2 / 3 ) :
pitchtol + pitch / 4 / sqrt ( 3 ) , // Internal case
minortol = tolerance = = "1B" || tolerance = = "2B" ?
(
d < 0.25 ? constrain ( 0.05 * pow ( P , 2 / 3 ) + 0.03 * P / d - 0.002 , 0.25 * P - 0.4 * P * P , 0.394 * P )
: ( P > 0.25 ? 0.15 * P : 0.25 * P - 0.4 * P * P )
) :
tolerance = = "3B" ? constrain ( 0.05 * pow ( P , 2 / 3 ) + 0.03 * P / d - 0.002 , P < 1 / 13 ? 0.12 * P : 0.23 * P - 1.5 * P * P , 0.394 * P )
: 0 , // not used for external threads
//f=echo(allowance=allowance),
//g=echo(pta2 = pitchtol_2A),
// ff=echo(minortol=minortol, pitchtol=pitchtol, majortol=majortol),
basic_minordiam = d - 5 / 4 * H ,
basic_pitchdiam = d - 3 / 4 * H ,
majordiam = internal ? [ d , d ] : // A little confused here, paragraph 8.3.2
[ d - allowance - majortol , d - allowance ] ,
//ffda=echo(allowance=allowance, majortol=majortol, "*****************************"),
pitchdiam = internal ? [ basic_pitchdiam , basic_pitchdiam + pitchtol ]
: [ majordiam [ 1 ] - 3 / 4 * H - pitchtol , majordiam [ 1 ] - 3 / 4 * H ] ,
minordiam = internal ? [ basic_minordiam , basic_minordiam + minortol ]
: [ pitchdiam [ 0 ] - 3 / 4 * H , basic_minordiam - allowance - H / 8 ] // the -H/8 is for the UNR case, 0 for UN case
)
[ [ "pitch" , P * INCH ] , [ "d_major" , majordiam * INCH ] , [ "d_pitch" , pitchdiam * INCH ] , [ "d_minor" , minordiam * INCH ] ,
[ "basic" , INCH * [ basic_minordiam , basic_pitchdiam , d ] ] ] ;
function _exact_thread_tolerance ( d , P ) =
let (
H = P * sqrt ( 3 ) / 2 ,
basic_minordiam = d - 5 / 4 * H ,
basic_pitchdiam = d - 3 / 4 * H
)
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[ [ "pitch" , P ] , [ "d_major" , [ d , d ] ] , [ "d_pitch" , [ basic_pitchdiam , basic_pitchdiam ] ] , [ "d_minor" , [ basic_minordiam , basic_minordiam ] ] ,
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[ "basic" , [ basic_minordiam , basic_pitchdiam , d ] ] ] ;
// Module: nut()
// Usage:
// nut([name], diameter, thickness, [thread=], [oversize=], [spec=], [tolerance=], [$slop=]) [ATTACHMENTS];
// Description:
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// Generates a hexagonal nut. See [screw parameters](#section-screw-parameters) for details on the parameters that define a nut.
// As for screws, you can give the specification in `spec` and then omit the name. The diameter is the flat-to-flat
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// size of the nut produced.
// .
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// The tolerance determines the actual thread sizing based on the nominal size in accordance with standards.
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// The $slop parameter determines extra gaps left to account for printing overextrusion. It defaults to 0.
// Arguments:
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// name = screw specification, e.g. "M5x1" or "#8-32". See [screw naming](#subsection-screw-naming).
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// diameter = outside diameter of nut (flat to flat dimension)
// thickness = thickness of nut (in mm)
// ---
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// thread = thread type or specification. See [screw pitch](#subsection-standard-screw-pitch). Default: "coarse"
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// oversize = amount to increase screw diameter for clearance holes. Default: 0
// spec = screw specification from `screw_info()`. If you specify this you can omit all the preceeding parameters.
// bevel = bevel the nut. Default: false
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// tolerance = nut tolerance. Determines actual nut thread geometry based on nominal sizing. See [tolerance](#subsection-tolerance). Default is "2B" for UTS and "6H" for ISO.
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// $slop = extra space left to account for printing over-extrusion. Default: 0
// anchor = Translate so anchor point is at origin (0,0,0). See [anchor](attachments.scad#subsection-anchor). Default: `CENTER`
// spin = Rotate this many degrees around the Z axis after anchor. See [spin](attachments.scad#subsection-spin). Default: `0`
// orient = Vector to rotate top towards, after spin. See [orient](attachments.scad#subsection-orient). Default: `UP`
// Example: A metric and UTS nut
// nut("3/8", 5/8*INCH, 1/4*INCH);
// right(25)
// nut("M8", 16, 6);
// Example: The three different UTS nut tolerances
// module mark(number)
// {
// difference(){
// children();
// ycopies(n=number, spacing=1.5)right(.25*INCH-2)up(8-.35)cyl(d=1, h=1);
// }
// }
// $fn=64;
// xdistribute(spacing=17){
// mark(1) nut("1/4-20", thickness=8, diameter=0.5*INCH,tolerance="1B");
// mark(2) nut("1/4-20", thickness=8, diameter=0.5*INCH,tolerance="2B");
// mark(3) nut("1/4-20", thickness=8, diameter=0.5*INCH,tolerance="3B");
// }
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function nut ( name , diameter , thickness , thread = "coarse" , spec , tolerance = undef ,
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bevel = false , anchor = BOTTOM , spin = 0 , orient = UP ) = no_function ( "nut" ) ;
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module nut ( name , diameter , thickness , thread = "coarse" , spec , tolerance = undef ,
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bevel = false , anchor = BOTTOM , spin = 0 , orient = UP , oversize = 0 )
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{
assert ( is_num ( diameter ) && diameter > 0 ) ;
assert ( is_num ( thickness ) && thickness > 0 ) ;
spec = is_def ( spec ) ? spec : screw_info ( name , thread = thread , oversize = oversize ) ;
threadspec = thread_specification ( spec , internal = true , tolerance = tolerance ) ;
echo ( threadspec = threadspec , "for nut threads" ) ;
echo ( nut_minor_diam = mean ( struct_val ( threadspec , "d_minor" ) ) ) ;
threaded_nut (
od = diameter ,
id = [ mean ( struct_val ( threadspec , "d_minor" ) ) ,
mean ( struct_val ( threadspec , "d_pitch" ) ) ,
mean ( struct_val ( threadspec , "d_major" ) ) ] ,
pitch = struct_val ( threadspec , "pitch" ) ,
h = thickness ,
bevel = bevel ,
anchor = anchor , spin = spin , orient = orient ) children ( ) ;
}
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// Takes a screw name as input and returns a list of the form
// [system, diameter, thread, length]
// where system is either "english" or "metric".
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function _parse_screw_name ( name ) =
let ( commasplit = str_split ( name , "," ) ,
length = parse_num ( commasplit [ 1 ] ) ,
xdash = str_split ( commasplit [ 0 ] , "-x" ) ,
type = xdash [ 0 ] ,
thread = parse_float ( xdash [ 1 ] )
)
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assert ( len ( commasplit ) < = 2 , str ( "More than one comma found in screw name, \"" , name , "\"" ) )
assert ( len ( xdash ) < = 2 , str ( "Screw name has too many '-' or 'x' characters, \"" , name , "\"" ) )
assert ( len ( commasplit ) = = 1 || is_num ( length ) , str ( "Invalid length in screw name, \"" , name , "\"" ) )
assert ( len ( xdash ) = = 1 || all_nonnegative ( thread ) , str ( "Thread pitch not a valid number in screw name, \"" , name , "\"" ) )
type [ 0 ] = = "M" || type [ 0 ] = = "m" ?
let ( diam = parse_float ( substr ( type , 1 ) ) )
assert ( is_num ( diam ) , str ( "Screw size must be a number in screw name, \"" , name , "\"" ) )
[ "metric" , parse_float ( substr ( type , 1 ) ) , thread , length ]
:
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let (
diam = type [ 0 ] = = "#" ? type :
suffix ( type , 2 ) = = "''" ? parse_float ( substr ( type , 0 , len ( type ) - 2 ) ) :
let ( val = parse_num ( type ) )
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assert ( all_positive ( val ) , str ( "Screw size must be a number in screw name, \"" , name , "\"" ) )
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val = = floor ( val ) && val >= 0 && val < = 12 ? str ( "#" , type ) : val
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)
assert ( is_str ( diam ) || is_num ( diam ) , str ( "Invalid screw diameter in screw name, \"" , name , "\"" ) )
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[ "english" , diam , thread , u_mul ( 25.4 , length ) ] ;
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// drive can be "hex", "phillips", "slot", "torx", or "none"
// or you can specify "ph0" up to "ph4" for phillips and "t20" for torx 20
function _parse_drive ( drive = undef , drive_size = undef ) =
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is_undef ( drive ) ? [ "none" , undef ]
: assert ( is_string ( drive ) )
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let ( drive = downcase ( drive ) )
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in_list ( drive , [ "hex" , "phillips" , "slot" , "torx" , "phillips" , "none" ] ) ? [ drive , drive_size ]
: drive [ 0 ] = = "t" ? let ( size = parse_int ( substr ( drive , 1 ) ) ) [ "torx" , size , torx_depth ( size ) ]
: starts_with ( drive , "ph" ) && search ( drive [ 2 ] , "01234" ) ! = [ ] ? [ "phillips" , ord ( drive [ 2 ] ) - ord ( "0" ) ]
: assert ( false , str ( "Unknown screw drive type " , drive ) ) ;
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// Module: screw_head()
// Usage:
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// screw_head(screw_info, [details],[counterbore],[flat_height])
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// Description:
// Draws the screw head described by the data structure `screw_info`, which
// should have the fields produced by {{screw_info()}}. See that function for
// details on the fields. Standard orientation is with the head centered at (0,0)
// and oriented in the +z direction. Flat heads appear below the xy plane.
// Other heads appear sitting on the xy plane.
// Arguments:
// screw_info = structure produced by {{screw_info()}}
// details = true for more detailed model. Default: false
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function screw_head ( screw_info , details = false ) = no_function ( "screw_head" ) ;
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module screw_head ( screw_info , details = false , counterbore = 0 , flat_height ) {
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no_children ( $children ) ;
head = struct_val ( screw_info , "head" ) ;
head_size = struct_val ( screw_info , "head_size" ) ;
head_height = struct_val ( screw_info , "head_height" ) ;
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dum0 = assert ( is_def ( head_height ) || in_list ( head , [ "flat" , "none" ] ) , "Undefined head height only allowed with flat head or headless screws" ) ;
heightok = ( is_undef ( head_height ) && in_list ( head , [ "flat" , "none" ] ) ) || all_positive ( head_height ) ;
dum1 = assert ( heightok , "Head hight must be a postive number" ) ;
dum2 = assert ( counterbore = = 0 || counterbore = = false || head ! = "none" , "Cannot counterbore a headless screw" ) ;
counterbore = counterbore = = false ? 0
: head ! = "flat" && counterbore = = true ? head_height
: counterbore ;
assert ( all_nonnegative ( counterbore ) , str ( counterbore = = true ? "Must specify numerical counterbore height with flat head screw"
: "Counterbore must be a nonnegative number" ) ) ;
if ( head ! = "flat" && counterbore > 0 )
cyl ( d = head = = "hex" ? 2 * head_size / sqrt ( 3 ) : head_size , l = counterbore , anchor = BOTTOM ) ;
if ( head = = "flat" ) { // For flat head, counterbore is integrated
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angle = struct_val ( screw_info , "head_angle" ) / 2 ;
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diam = struct_val ( screw_info , "diameter" ) ;
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full_height = head_size / 2 / tan ( angle ) ;
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// if head_height is set we are making an undercut flat head
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height = first_defined ( [ head_height , flat_height , full_height ] ) ;
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r1 = head_size / 2 ;
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r2 = r1 * ( 1 - height / full_height ) ;
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rotate_extrude ( )
polygon ( [ [ 0 , - height ] , [ r2 , - height ] , [ r1 , 0 ] , if ( counterbore > 0 ) [ r1 , counterbore ] , [ 0 , counterbore ] ] ) ;
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}
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if ( head ! = "flat" && first_defined ( [ head_height , 0 ] ) > counterbore ) {
if ( in_list ( head , [ "round" , "pan round" , "button" , "fillister" , "cheese" ] ) ) {
base = head = = "fillister" ? 0.75 * head_height :
head = = "pan round" ? . 6 * head_height :
head = = "cheese" ? . 7 * head_height :
0.1 * head_height ; // round and button
head_size2 = head = = "cheese" ? head_size - 2 * tan ( 5 ) * head_height : head_size ; // 5 deg slope on cheese head
cyl ( l = base , d1 = head_size , d2 = head_size2 , anchor = BOTTOM )
attach ( TOP )
rotate_extrude ( )
intersection ( ) {
arc ( points = [ [ - head_size2 / 2 , 0 ] , [ 0 , - base + head_height * ( head = = "button" ? 4 / 3 : 1 ) ] , [ head_size2 / 2 , 0 ] ] ) ;
square ( [ head_size2 , head_height - base ] ) ;
}
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}
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if ( head = = "pan flat" )
cyl ( l = head_height , d = head_size , rounding2 = 0.2 * head_size , anchor = BOTTOM ) ;
if ( head = = "socket" )
cyl ( l = head_height , d = head_size , anchor = BOTTOM , chamfer2 = details ? struct_val ( screw_info , "diameter" ) / 10 : undef ) ;
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if ( head = = "socket ribbed" ) {
// These numbers are based on ISO specifications that dictate how much oversizsed a ribbed socket head can be
// We are making our ribbed heads the same size as unribbed (by cutting the ribbing away), but these numbers are presumably a good guide
rib_size = [ [ 2 , . 09 ] ,
[ 3 , . 09 ] ,
[ 6 , . 11 ] ,
[ 12 , . 135 ] ,
[ 20 , . 165 ] ] ;
diam = struct_val ( screw_info , "diameter" ) ;
intersection ( ) {
cyl ( h = head_height / 4 , d = head_size , anchor = BOT )
attach ( TOP ) cyl ( l = head_height * 3 / 4 , d = head_size , anchor = BOT , texture = "trunc_ribs" , tex_counts = [ 31 , 1 ] , tex_scale = - lookup ( diam , rib_size ) ) ;
cyl ( h = head_height , d = head_size , chamfer2 = diam / 10 , anchor = BOT ) ;
}
}
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if ( head = = "hex" )
intersection ( ) {
linear_extrude ( height = head_height ) hexagon ( id = head_size ) ;
if ( details )
down ( . 01 ) cyl ( l = head_height + . 02 , d = 2 * head_size / sqrt ( 3 ) , chamfer = head_size * ( 1 / sqrt ( 3 ) - 1 / 2 ) , anchor = BOTTOM ) ;
}
}
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}
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// Function: screw_info()
// Usage:
// info = screw_info(name, [head], [drive], [thread=], [drive_size=], [oversize=])
//
// Description:
// Look up screw characteristics for the specified screw type.
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// See [screw parameters](#section-screw-parameters) for details on the parameters that define a screw.
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// .
// The `oversize=` parameter adds the specified amount to the screw and head diameter to make an
// oversized screw. This is intended for generating clearance holes, not for dealing with printer
// inaccuracy. Does not affect length, thread pitch or head height.
// .
// The output is a [[struct|structs.scad]] with the following fields:
// .
// Field | What it is
// ------------------ | ---------------
// `"system"` | Either `"UTS"` or `"ISO"` (used for correct tolerance computation).
// `"diameter"` | The nominal diameter of the screw shaft in mm.
// `"pitch"` | The thread pitch in mm.
// `"head"` | The type of head (a string from the list above).
// `"head_size"` | Size of the head in mm.
// `"head_angle"` | Countersink angle for flat heads.
// `"head_height"` | Height of the head (when needed to specify the head).
// `"drive"` | The drive type (`"phillips"`, `"torx"`, `"slot"`, `"hex"`, `"none"`)
// `"drive_size"` | The drive size, either a drive number (phillips or torx) or a dimension in mm (hex). Not defined for slot drive.
// `"drive_diameter"` | Diameter of a phillips drive.
// `"drive_width"` | Width of the arms of the cross in a phillips drive or the slot for a slot drive.
// `"drive_depth"` | Depth of the drive recess.
// `"length"` | Length of the screw in mm measured in the customary fashion. For flat head screws the total length and for other screws, the length from the bottom of the head to the screw tip.
//
// Arguments:
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// name = screw specification, e.g. "M5x1" or "#8-32". See [screw naming](#subsection-screw-naming).
// head = head type. See [screw heads](#subsection-screw-heads) Default: none
// drive = drive type. See [screw heads](#subsection-screw-heads) Default: none
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// ---
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// thread = thread type or specification. See [screw pitch](#subsection-standard-screw-pitch). Default: "coarse"
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// drive_size = size of drive recess to override computed value
// oversize = amount to increase screw diameter for clearance holes. Default: 0
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function screw_info ( name , head = "none" , drive , thread = "coarse" , drive_size = undef , oversize = 0 ) =
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let ( type = _parse_screw_name ( name ) ,
drive_info = _parse_drive ( drive , drive_size ) ,
drive = drive_info [ 0 ] ,
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screwdata =
type [ 0 ] = = "english" ? _screw_info_english ( type [ 1 ] , type [ 2 ] , head , thread , drive )
: type [ 0 ] = = "metric" ? _screw_info_metric ( type [ 1 ] , type [ 2 ] , head , thread , drive )
: [ ] ,
over_ride = concat (
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len ( drive_info ) >= 3 ? [ "drive_depth" , drive_info [ 2 ] ] : [ ] ,
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is_def ( type [ 3 ] ) ? [ "length" , type [ 3 ] ] : [ ] ,
is_def ( drive_info [ 1 ] ) ? [ "drive_size" , drive_info [ 1 ] ] : [ ] ,
[ "diameter" , oversize + struct_val ( screwdata , "diameter" ) ,
"head_size" , u_add ( oversize , struct_val ( screwdata , "head_size" ) ) ]
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)
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)
struct_set ( screwdata , over_ride ) ;
function _screw_info_english ( diam , threadcount , head , thread , drive ) =
let (
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diameter = is_string ( diam ) ? parse_int ( substr ( diam , 1 ) ) * 0.013 + 0.06
: diam ,
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pitch =
is_num ( thread ) ? thread :
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thread = = "none" ? 0 :
is_def ( threadcount ) ? INCH / threadcount :
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let (
tind = struct_val ( [ [ "coarse" , 0 ] , [ "unc" , 0 ] ,
[ "fine" , 1 ] , [ "unf" , 1 ] ,
[ "extra fine" , 2 ] , [ "extrafine" , 2 ] , [ "unef" , 2 ] ] ,
downcase ( thread ) ) ,
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dummy = assert ( is_def ( tind ) , str ( "Unknown thread type, \"" , thread , "\"" ) ) ,
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// coarse fine xfine
// UNC UNF UNEF
UTS_thread = [
[ "#0" , [ undef , 80 , undef ] ] ,
[ "#1" , [ 64 , 72 , undef ] ] ,
[ "#2" , [ 56 , 64 , undef ] ] ,
[ "#3" , [ 48 , 56 , undef ] ] ,
[ "#4" , [ 40 , 48 , undef ] ] ,
[ "#5" , [ 40 , 44 , undef ] ] ,
[ "#6" , [ 32 , 40 , undef ] ] ,
[ "#8" , [ 32 , 36 , undef ] ] ,
[ "#10" , [ 24 , 32 , undef ] ] ,
[ "#12" , [ 24 , 28 , 32 ] ] ,
[ 1 / 4 , [ 20 , 28 , 32 ] ] ,
[ 5 / 16 , [ 18 , 24 , 32 ] ] ,
[ 3 / 8 , [ 16 , 24 , 32 ] ] ,
[ 7 / 16 , [ 14 , 20 , 28 ] ] ,
[ 1 / 2 , [ 13 , 20 , 28 ] ] ,
[ 9 / 16 , [ 12 , 18 , 24 ] ] ,
[ 5 / 8 , [ 11 , 18 , 24 ] ] ,
[ 3 / 4 , [ 10 , 16 , 20 ] ] ,
[ 7 / 8 , [ 9 , 14 , 20 ] ] ,
[ 1 , [ 8 , 12 , 20 ] ] ,
[ 1.125 , [ 7 , 12 , 18 ] ] ,
[ 1.25 , [ 7 , 12 , 18 ] ] ,
[ 1.375 , [ 6 , 12 , 18 ] ] ,
[ 1.5 , [ 6 , 12 , 18 ] ] ,
[ 1.75 , [ 5 , undef , undef ] ] ,
[ 2 , [ 4.5 , undef , undef ] ] ,
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] ,
tentry = struct_val ( UTS_thread , diam )
)
assert ( is_def ( tentry ) , str ( "Unknown screw size, \"" , diam , "\"" ) )
INCH / tentry [ tind ] ,
head_data =
head = = "none" ? let (
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UTS_setscrew = [ // hex width, hex depth
[ "#0" , [ 0.028 , 0.050 ] ] ,
[ "#1" , [ 0.035 , 0.060 ] ] ,
[ "#2" , [ 0.035 , 0.060 ] ] ,
[ "#3" , [ 0.05 , 0.070 ] ] ,
[ "#4" , [ 0.05 , 0.045 , 6 , 0.027 ] ] ,
[ "#5" , [ 1 / 16 , 0.080 , 7 , 0.036 ] ] ,
[ "#6" , [ 1 / 16 , 0.080 , 7 , 0.036 ] ] ,
[ "#8" , [ 5 / 64 , 0.090 , 8 , 0.041 ] ] ,
[ "#10" , [ 3 / 32 , 0.100 , 10 , 0.049 ] ] ,
[ 1 / 4 , [ 1 / 8 , 0.125 , 15 , 0.068 ] ] ,
[ 5 / 16 , [ 5 / 32 , 0.156 , 25 , 0.088 ] ] ,
[ 3 / 8 , [ 3 / 16 , 0.188 , 30 , 0.097 ] ] ,
[ 7 / 16 , [ 7 / 32 , 0.219 , 40 , 0.117 ] ] ,
[ 1 / 2 , [ 1 / 4 , 0.250 , 45 , 0.137 ] ] ,
[ 5 / 8 , [ 5 / 16 , 0.312 , 55 , 0.202 ] ] ,
[ 3 / 4 , [ 3 / 8 , 0.375 , 60 , 0.202 ] ] ,
[ 7 / 8 , [ 1 / 2 , 0.500 , 70 , 0.291 ] ] ,
[ 1 , [ 9 / 16 , 0.562 , 70 , 0.291 ] ] ,
[ 1.125 , [ 9 / 16 , 0.562 ] ] ,
[ 1.25 , [ 5 / 8 , 0.625 ] ] ,
[ 1.375 , [ 5 / 8 , 0.625 ] ] ,
[ 1.5 , [ 3 / 4 , 0.750 ] ] ,
[ 1.75 , [ 1 , 1.000 ] ] ,
[ 2 , [ 1 , 1.000 ] ] ,
] ,
entry = struct_val ( UTS_setscrew , diam ) ,
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dummy = assert ( is_def ( entry ) , str ( "Screw size " , diam , " unsupported for headless screws" ) ) ,
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drive_dims = drive = = "hex" ? [ [ "drive_size" , INCH * entry [ 0 ] ] , [ "drive_depth" , INCH * entry [ 1 ] ] ] :
drive = = "torx" ? [ [ "drive_size" , entry [ 2 ] ] , [ "drive_depth" , INCH * entry [ 3 ] ] ] : [ ]
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) concat ( [ [ "head" , "none" ] ] , drive_dims )
: head = = "hex" ? let (
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UTS_hex = [
// flat to flat width, height
[ "#2" , [ 1 / 8 , 1 / 16 ] ] ,
[ "#4" , [ 3 / 16 , 1 / 16 ] ] ,
[ "#6" , [ 1 / 4 , 3 / 32 ] ] ,
[ "#8" , [ 1 / 4 , 7 / 64 ] ] ,
[ "#10" , [ 5 / 16 , 1 / 8 ] ] ,
[ "#12" , [ 5 / 16 , 5 / 32 ] ] ,
[ 1 / 4 , [ 7 / 16 , 5 / 32 ] ] ,
[ 5 / 16 , [ 1 / 2 , 13 / 64 ] ] ,
[ 3 / 8 , [ 9 / 16 , 1 / 4 ] ] ,
[ 7 / 16 , [ 5 / 8 , 19 / 64 ] ] ,
[ 1 / 2 , [ 3 / 4 , 11 / 32 ] ] ,
[ 9 / 16 , [ 13 / 16 , 23 / 64 ] ] ,
[ 5 / 8 , [ 15 / 16 , 27 / 64 ] ] ,
[ 3 / 4 , [ 1.125 , 1 / 2 ] ] ,
[ 7 / 8 , [ 1 + 5 / 16 , 37 / 64 ] ] ,
[ 1 , [ 1.5 , 43 / 64 ] ] ,
[ 1.125 , [ 1 + 11 / 16 , 11 / 16 ] ] ,
[ 1.25 , [ 1 + 7 / 8 , 27 / 32 ] ] ,
[ 1.5 , [ 2.25 , 15 / 16 ] ] ,
[ 1.75 , [ 2 + 5 / 8 , 1 + 3 / 32 ] ] ,
[ 2 , [ 3 , 1 + 7 / 32 ] ] ,
] ,
entry = struct_val ( UTS_hex , diam )
)
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assert ( is_def ( entry ) , str ( "Screw size " , diam , " unsupported for head type \"" , head , "\"" ) )
[ [ "head" , "hex" ] , [ "head_size" , INCH * entry [ 0 ] ] , [ "head_height" , INCH * entry [ 1 ] ] ]
: in_list ( head , [ "socket" , "socket ribbed" ] ) ? let (
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UTS_socket = [ // height = screw diameter
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//diam, hex, torx size, hex depth, torx depth
[ "#0" , [ 0.096 , 0.05 , 6 , 0.025 , 0.027 ] ] ,
[ "#1" , [ 0.118 , 1 / 16 , 7 , 0.031 , 0.036 ] ] ,
[ "#2" , [ 9 / 64 , 5 / 64 , 8 , 0.038 , 0.037 ] ] ,
[ "#3" , [ 0.161 , 5 / 64 , 8 , 0.044 , 0.041 ] ] , // For larger sizes, hex recess depth is
[ "#4" , [ 0.183 , 3 / 32 , 10 , 0.051 , 0.049 ] ] , // half the diameter
[ "#5" , [ 0.205 , 3 / 32 , 10 , 0.057 , 0.049 ] ] ,
[ "#6" , [ 0.226 , 7 / 64 , 15 , 0.064 , 0.058 ] ] ,
[ "#8" , [ 0.270 , 9 / 64 , 25 , 0.077 , 0.078 ] ] ,
[ "#10" , [ 5 / 16 , 5 / 32 , 27 , undef , 0.088 ] ] ,
[ "#12" , [ 0.324 , 5 / 32 , undef , undef , undef ] ] ,
[ 1 / 4 , [ 3 / 8 , 3 / 16 , 30 , undef , 0.097 ] ] ,
[ 5 / 16 , [ 15 / 32 , 1 / 4 , 45 , undef , 0.137 ] ] ,
[ 3 / 8 , [ 9 / 16 , 5 / 16 , 50 , undef , 0.155 ] ] ,
[ 7 / 16 , [ 21 / 32 , 3 / 8 , 55 , undef , 0.202 ] ] ,
[ 1 / 2 , [ 3 / 4 , 3 / 8 , 55 , undef , 0.202 ] ] ,
[ 9 / 16 , [ 27 / 32 , 7 / 16 , undef , undef , undef ] ] ,
[ 5 / 8 , [ 15 / 16 , 1 / 2 , 70 , undef , 0.291 ] ] ,
[ 3 / 4 , [ 1.125 , 5 / 8 , 80 , undef , 0.332 ] ] ,
[ 7 / 8 , [ 1 + 5 / 16 , 3 / 4 , 100 , undef , 0.425 ] ] ,
[ 1 , [ 1.5 , 3 / 4 , 100 , undef , 0.425 ] ] ,
[ 1.125 , [ 1 + 11 / 16 , 7 / 8 , undef , undef , undef ] ] ,
[ 1.25 , [ 1 + 7 / 8 , 7 / 8 , undef , undef , undef ] ] ,
[ 1.375 , [ 2 + 1 / 16 , 1 , undef , undef , undef ] ] ,
[ 1.5 , [ 2.25 , 1 , undef , undef , undef ] ] ,
[ 1.75 , [ 2 + 5 / 8 , 1.25 , undef , undef , undef ] ] ,
[ 2 , [ 3 , 1.5 , undef , undef , undef ] ] ,
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] ,
entry = struct_val ( UTS_socket , diam ) ,
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dummy = assert ( is_def ( entry ) , str ( "Screw size " , diam , " unsupported for head type \"" , head , "\"" ) ) ,
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hexdepth = is_def ( entry [ 3 ] ) ? entry [ 3 ]
: is_def ( diam ) ? diam / 2
: undef ,
drive_size = drive = = "hex" ? [ [ "drive_size" , INCH * entry [ 1 ] ] , [ "drive_depth" , INCH * hexdepth ] ] :
drive = = "torx" ? [ [ "drive_size" , entry [ 2 ] ] , [ "drive_depth" , INCH * entry [ 4 ] ] ] : [ ]
)
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concat ( [ [ "head" , head ] , [ "head_size" , INCH * entry [ 0 ] ] , [ "head_height" , INCH * diameter ] ] , drive_size )
: head = = "pan" ? let (
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UTS_pan = [ // pan head for phillips or slotted
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// head height
// diam, slotted phillips phillips drive, phillips diam, phillips width, phillips depth, slot width, slot depth torx size
[ "#0" , [ 0.116 , 0.039 , 0.044 , 0 , 0.067 , 0.013 , 0.039 , 0.023 , 0.022 ] ] ,
[ "#1" , [ 0.142 , 0.046 , 0.053 , 0 , 0.085 , 0.015 , 0.049 , 0.027 , 0.027 ] ] ,
[ "#2" , [ 0.167 , 0.053 , 0.063 , 1 , 0.104 , 0.017 , 0.059 , 0.031 , 0.031 , 8 ] ] ,
[ "#3" , [ 0.193 , 0.060 , 0.071 , 1 , 0.112 , 0.019 , 0.068 , 0.035 , 0.036 ] ] ,
[ "#4" , [ 0.219 , 0.068 , 0.080 , 1 , 0.122 , 0.019 , 0.078 , 0.039 , 0.040 , 10 ] ] ,
[ "#5" , [ 0.245 , 0.075 , 0.089 , 2 , 0.158 , 0.028 , 0.083 , 0.043 , 0.045 ] ] ,
[ "#6" , [ 0.270 , 0.082 , 0.097 , 2 , 0.166 , 0.028 , 0.091 , 0.048 , 0.050 , 15 ] ] ,
[ "#8" , [ 0.322 , 0.096 , 0.115 , 2 , 0.182 , 0.030 , 0.108 , 0.054 , 0.058 , 20 ] ] ,
[ "#10" , [ 0.373 , 0.110 , 0.133 , 2 , 0.199 , 0.031 , 0.124 , 0.060 , 0.068 , 25 ] ] ,
[ "#12" , [ 0.425 , 0.125 , 0.151 , 3 , 0.259 , 0.034 , 0.141 , 0.067 , 0.077 ] ] ,
[ 1 / 4 , [ 0.492 , 0.144 , 0.175 , 3 , 0.281 , 0.036 , 0.161 , 0.075 , 0.087 , 30 ] ] ,
[ 5 / 16 , [ 0.615 , 0.178 , 0.218 , 4 , 0.350 , 0.059 , 0.193 , 0.084 , 0.106 ] ] ,
[ 3 / 8 , [ 0.740 , 0.212 , 0.261 , 4 , 0.389 , 0.065 , 0.233 , 0.094 , 0.124 ] ] ,
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] ,
htind = drive = = "slot" ? 1 : 2 ,
entry = struct_val ( UTS_pan , diam ) ,
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dummy = assert ( is_def ( entry ) , str ( "Screw size " , diam , " unsupported for head type \"" , head , "\"" ) ) ,
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drive_size = drive = = "phillips" ? [ [ "drive_size" , entry [ 3 ] ] , [ "drive_diameter" , INCH * entry [ 4 ] ] , [ "drive_width" , INCH * entry [ 5 ] ] , [ "drive_depth" , INCH * entry [ 6 ] ] ] :
[ [ "drive_width" , INCH * entry [ 7 ] ] , [ "drive_depth" , INCH * entry [ 8 ] ] ] )
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concat ( [ [ "head" , "pan round" ] , [ "head_size" , INCH * entry [ 0 ] ] , [ "head_height" , INCH * entry [ htind ] ] ] , drive_size )
: head = = "button" || head = = "round" ? let (
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UTS_button = [ // button, hex or torx drive
// head diam, height, phillips, hex, torx, hex depth
[ "#0" , [ 0.114 , 0.032 , undef , 0.035 , 5 , 0.020 , 0.017 ] ] ,
[ "#1" , [ 0.139 , 0.039 , undef , 3 / 64 , 5 , 0.028 , 0.020 ] ] ,
[ "#2" , [ 0.164 , 0.046 , undef , 3 / 64 , 6 , 0.028 , 0.023 ] ] ,
[ "#3" , [ 0.188 , 0.052 , undef , 1 / 16 , undef , 0.035 , undef ] ] ,
[ "#4" , [ 0.213 , 0.059 , undef , 1 / 16 , 8 , 0.035 , 0.032 ] ] ,
[ "#5" , [ 0.238 , 0.066 , undef , 5 / 64 , undef , 0.044 , undef ] ] ,
[ "#6" , [ 0.262 , 0.073 , undef , 5 / 64 , 10 , 0.044 , 0.038 ] ] ,
[ "#8" , [ 0.312 , 0.087 , undef , 3 / 32 , 15 , 0.052 , 0.045 ] ] ,
[ "#10" , [ 0.361 , 0.101 , undef , 1 / 8 , 25 , 0.070 , 0.052 ] ] ,
[ "#12" , [ 0.413 , 0.114 , undef , 1 / 8 , undef , 0.070 , undef ] ] , // also 0.410, .115, 9/64, hex depth guessed
[ 1 / 4 , [ 0.437 , 0.132 , undef , 5 / 32 , 27 , 0.087 , 0.068 ] ] ,
[ 5 / 16 , [ 0.547 , 0.166 , undef , 3 / 16 , 40 , 0.105 , 0.090 ] ] ,
[ 3 / 8 , [ 0.656 , 0.199 , undef , 7 / 32 , 45 , 0.122 , 0.106 ] ] ,
[ 7 / 16 , [ 0.750 , 0.220 , undef , 1 / 4 , undef , 0.193 , undef ] ] , // hex depth interpolated
[ 1 / 2 , [ 0.875 , 0.265 , undef , 5 / 16 , 55 , 0.175 , 0.158 ] ] ,
[ 5 / 8 , [ 1.000 , 0.331 , undef , 3 / 8 , 60 , 0.210 , 0.192 ] ] ,
[ 3 / 4 , [ 1.1 , 0.375 , undef , 7 / 16 , undef , 0.241 ] ] , // hex depth extrapolated
] ,
UTS_round = [ // slotted, phillips
// head diam, head height, phillips drive, hex, torx, ph diam, ph width, ph depth, slot width, slot depth
[ "#0" , [ 0.113 , 0.053 , 0 , undef , undef ] ] ,
[ "#1" , [ 0.138 , 0.061 , 0 , undef , undef ] ] ,
[ "#2" , [ 0.162 , 0.069 , 1 , undef , undef , 0.100 , 0.017 , 0.053 , 0.031 , 0.048 ] ] ,
[ "#3" , [ 0.187 , 0.078 , 1 , undef , undef , 0.109 , 0.018 , 0.062 , 0.035 , 0.053 ] ] ,
[ "#4" , [ 0.211 , 0.086 , 1 , undef , undef , 0.118 , 0.019 , 0.072 , 0.039 , 0.058 ] ] ,
[ "#5" , [ 0.236 , 0.095 , 2 , undef , undef , 0.154 , 0.027 , 0.074 , 0.043 , 0.063 ] ] ,
[ "#6" , [ 0.260 , 0.103 , 2 , undef , undef , 0.162 , 0.027 , 0.084 , 0.048 , 0.068 ] ] ,
[ "#8" , [ 0.309 , 0.120 , 2 , undef , undef , 0.178 , 0.030 , 0.101 , 0.054 , 0.077 ] ] ,
[ "#10" , [ 0.359 , 0.137 , 2 , undef , undef , 0.195 , 0.031 , 0.119 , 0.060 , 0.087 ] ] ,
[ "#12" , [ 0.408 , 0.153 , 3 , undef , undef , 0.249 , 0.032 , 0.125 , 0.067 , 0.096 ] ] ,
[ 1 / 4 , [ 0.472 , 0.175 , 3 , undef , undef , 0.268 , 0.034 , 0.147 , 0.075 , 0.109 ] ] ,
[ 5 / 16 , [ 0.590 , 0.216 , 3 , undef , undef , 0.308 , 0.040 , 0.187 , 0.084 , 0.132 ] ] ,
[ 3 / 8 , [ 0.708 , 0.256 , 4 , undef , undef , 0.387 , 0.064 , 0.228 , 0.094 , 0.155 ] ] ,
[ 1 / 2 , [ 0.813 , 0.355 , 4 , undef , undef , 0.416 , 0.068 , 0.256 , 0.106 , 0.211 ] ]
] ,
entry = struct_val ( head = = "button" ? UTS_button : UTS_round , diam ) ,
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dummy = assert ( is_def ( entry ) , str ( "Screw size " , diam , " unsupported for head type \"" , head , "\"" ) ) ,
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drive_index = drive = = "phillips" ? 2 :
drive = = "hex" ? 3 :
drive = = "torx" ? 4 : undef ,
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drive_size = drive = = "phillips" && head = = "round" ? [ [ "drive_size" , entry [ 2 ] ] , [ "drive_diameter" , u_mul ( INCH , entry [ 5 ] ) ] ,
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[ "drive_width" , INCH * entry [ 6 ] ] , [ "drive_depth" , INCH * entry [ 7 ] ] ] :
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drive = = "slot" && head = = "round" ? [ [ "drive_width" , INCH * entry [ 8 ] ] , [ "drive_depth" , u_mul ( INCH , entry [ 9 ] ) ] ] :
drive = = "hex" && head = = "button" ? [ [ "drive_size" , INCH * entry [ drive_index ] ] , [ "drive_depth" , u_mul ( INCH , entry [ 5 ] ) ] ] :
drive = = "torx" && head = = "button" ? [ [ "drive_size" , entry [ drive_index ] ] , [ "drive_depth" , u_mul ( INCH , entry [ 6 ] ) ] ] :
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is_def ( drive_index ) && head = = "button" ? [ [ "drive_size" , entry [ drive_index ] ] ] : [ ]
)
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concat ( [ [ "head" , head ] , [ "head_size" , INCH * entry [ 0 ] ] , [ "head_height" , INCH * entry [ 1 ] ] ] , drive_size )
: head = = "fillister" ? let (
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UTS_fillister = [ // head diam, head height, slot width, slot depth, phillips diam, phillips depth, phillips width, phillips #
[ "#0" , [ 0.096 , 0.055 , 0.023 , 0.025 , 0.067 , 0.039 , 0.013 , 0 ] ] ,
[ "#1" , [ 0.118 , 0.069 , 0.027 , 0.031 , 0.085 , 0.049 , 0.015 , ] ] ,
[ "#2" , [ 0.140 , 0.083 , 0.031 , 0.037 , 0.104 , 0.059 , 0.017 , ] ] ,
[ "#3" , [ 0.161 , 0.095 , 0.035 , 0.043 , 0.112 , 0.068 , 0.019 , 1 ] ] ,
[ "#4" , [ 0.183 , 0.107 , 0.039 , 0.048 , 0.122 , 0.078 , 0.019 , 1 ] ] ,
[ "#5" , [ 0.205 , 0.120 , 0.043 , 0.054 , 0.143 , 0.067 , 0.027 , 2 ] ] ,
[ "#6" , [ 0.226 , 0.132 , 0.048 , 0.060 , 0.166 , 0.091 , 0.028 , 2 ] ] ,
[ "#8" , [ 0.270 , 0.156 , 0.054 , 0.071 , 0.182 , 0.108 , 0.030 , 2 ] ] ,
[ "#10" , [ 0.313 , 0.180 , 0.060 , 0.083 , 0.199 , 0.124 , 0.031 , 2 ] ] ,
[ "#12" , [ 0.357 , 0.205 , 0.067 , 0.094 , 0.259 , 0.141 , 0.034 , 3 ] ] ,
[ 1 / 4 , [ 0.414 , 0.237 , 0.075 , 0.109 , 0.281 , 0.161 , 0.036 , 3 ] ] ,
[ 5 / 16 , [ 0.518 , 0.295 , 0.084 , 0.137 , 0.322 , 0.203 , 0.042 , 3 ] ] ,
[ 3 / 8 , [ 0.622 , 0.355 , 0.094 , 0.164 , 0.389 , 0.233 , 0.065 , 4 ] ] ,
] ,
entry = struct_val ( UTS_fillister , diam ) ,
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dummy = assert ( is_def ( entry ) , str ( "Screw size " , diam , " unsupported for head type \"" , head , "\"" ) ) ,
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drive_size = drive = = "phillips" ? [ [ "drive_size" , entry [ 7 ] ] , [ "drive_diameter" , INCH * entry [ 4 ] ] ,
[ "drive_width" , INCH * entry [ 6 ] ] , [ "drive_depth" , INCH * entry [ 5 ] ] ] :
drive = = "slot" ? [ [ "drive_width" , INCH * entry [ 2 ] ] , [ "drive_depth" , INCH * entry [ 3 ] ] ] : [ ]
)
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concat ( [ [ "head" , "fillister" ] , [ "head_size" , INCH * entry [ 0 ] ] , [ "head_height" , INCH * entry [ 1 ] ] ] , drive_size )
: in_list ( head , [ "flat" , "flat large" , "flat small" , "flat undercut" ] ) ? let (
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small = head = = "flat small" || head = = "flat undercut" || ( head = = "flat" && ( drive ! = "hex" && drive ! = "torx" ) ) ,
undercut = head = = "flat undercut" ,
UTS_flat_small = [ // for phillips drive, slotted, and torx
// diam, ph drive, torx drive, undercut height, phdiam, phdepth, phwidth, slotwidth, slotdepth, uc phdiam, uc phdepth, ucphwidth,ucslotdepth
[ "#0" , [ . 112 , 0 , undef , 0.025 , 0.062 , 0.035 , 0.014 , 0.023 , 0.015 , 0.062 , 0.035 , 0.014 , 0.011 ] ] ,
[ "#1" , [ . 137 , 0 , undef , 0.031 , 0.070 , 0.043 , 0.015 , 0.026 , 0.019 , 0.070 , 0.043 , 0.015 , 0.014 ] ] ,
[ "#2" , [ . 162 , 1 , 6 , 0.036 , 0.096 , 0.055 , 0.017 , 0.031 , 0.023 , 0.088 , 0.048 , 0.017 , 0.016 ] ] ,
[ "#3" , [ . 187 , 1 , undef , 0.042 , 0.100 , 0.060 , 0.018 , 0.035 , 0.027 , 0.099 , 0.059 , 0.018 , 0.019 ] ] ,
[ "#4" , [ . 212 , 1 , 8 , 0.047 , 0.122 , 0.081 , 0.018 , 0.039 , 0.030 , 0.110 , 0.070 , 0.018 , 0.022 ] ] ,
[ "#5" , [ . 237 , 2 , undef , 0.053 , 0.148 , 0.074 , 0.027 , 0.043 , 0.034 , 0.122 , 0.081 , 0.018 , 0.024 ] ] , // ph#1 for undercut
[ "#6" , [ . 262 , 2 , 10 , 0.059 , 0.168 , 0.094 , 0.029 , 0.048 , 0.038 , 0.140 , 0.066 , 0.025 , 0.027 ] ] ,
[ "#8" , [ . 312 , 2 , 15 , 0.070 , 0.182 , 0.110 , 0.030 , 0.054 , 0.045 , 0.168 , 0.094 , 0.029 , 0.032 ] ] ,
[ "#10" , [ . 362 , 2 , 20 , 0.081 , 0.198 , 0.124 , 0.032 , 0.060 , 0.053 , 0.182 , 0.110 , 0.030 , 0.037 ] ] ,
[ "#12" , [ . 412 , 3 , undef , 0.092 , 0.262 , 0.144 , 0.035 , 0.067 , 0.060 , 0.226 , 0.110 , 0.030 , 0.043 ] ] ,
[ 1 / 4 , [ . 477 , 3 , 27 , 0.107 , 0.276 , 0.160 , 0.036 , 0.075 , 0.070 , 0.244 , 0.124 , 0.032 , 0.050 ] ] ,
[ 5 / 16 , [ . 597 , 4 , 40 , 0.134 , 0.358 , 0.205 , 0.061 , 0.084 , 0.088 , 0.310 , 0.157 , 0.053 , 0.062 ] ] ,
[ 3 / 8 , [ . 717 , 4 , 40 , 0.161 , 0.386 , 0.234 , 0.065 , 0.094 , 0.106 , 0.358 , 0.205 , 0.061 , 0.075 ] ] ,
[ 1 / 2 , [ . 815 , 4 , undef , 0.156 , 0.418 , 0.265 , 0.069 , 0.106 , 0.103 , 0.402 , 0.252 , 0.068 , 0.072 ] ]
] ,
UTS_flat_large = [ // for hex drive, torx ASME B18.3
// head diam, hex drive size, torx size, hex depth, torx depth
[ "#0" , [ 0.138 , 1 / 32 , 3 , 0.025 , 0.016 ] ] ,
[ "#1" , [ 0.168 , 3 / 64 , 6 , 0.031 , 0.036 ] ] ,
[ "#2" , [ 0.197 , 3 / 64 , 6 , 0.038 , 0.036 ] ] ,
[ "#3" , [ 0.226 , 1 / 16 , 8 , 0.044 , 0.041 ] ] ,
[ "#4" , [ 0.255 , 1 / 16 , 10 , 0.055 , 0.038 ] ] ,
[ "#5" , [ 0.281 , 5 / 64 , 10 , 0.061 , 0.038 ] ] ,
[ "#6" , [ 0.307 , 5 / 64 , 15 , 0.066 , 0.045 ] ] ,
[ "#8" , [ 0.359 , 3 / 32 , 20 , 0.076 , 0.053 ] ] ,
[ "#10" , [ 0.411 , 1 / 8 , 25 , 0.087 , 0.061 ] ] ,
[ "#12" , [ 0.422 , 1 / 8 , undef , 0.111 , undef ] ] ,
[ 1 / 4 , [ 0.531 , 5 / 32 , 30 , 0.135 , 0.075 ] ] ,
[ 5 / 16 , [ 0.656 , 3 / 16 , 40 , 0.159 , 0.090 ] ] ,
[ 3 / 8 , [ 0.810 , 7 / 32 , 45 , 0.159 , 0.106 ] ] ,
[ 7 / 16 , [ 0.844 , 1 / 4 , 50 , 0.172 , 0.120 ] ] ,
[ 1 / 2 , [ 0.938 , 5 / 16 , 50 , 0.220 , 0.120 ] ] ,
[ 5 / 8 , [ 1.188 , 3 / 8 , 55 , 0.220 , 0.158 ] ] ,
[ 3 / 4 , [ 1.438 , 1 / 2 , 60 , 0.248 , 0.192 ] ] ,
[ 7 / 8 , [ 1.688 , 9 / 16 , undef , 0.297 , undef ] ] ,
[ 1 , [ 1.938 , 5 / 8 , undef , 0.325 , undef ] ] ,
[ 1.125 , [ 2.188 , 3 / 4 , undef , 0.358 , undef ] ] ,
[ 1.25 , [ 2.438 , 7 / 8 , undef , 0.402 , undef ] ] ,
[ 1.5 , [ 2.938 , 1 , undef , 0.435 , undef ] ] ,
] ,
entry = struct_val ( small ? UTS_flat_small : UTS_flat_large , diam ) ,
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dummy = assert ( is_def ( entry ) , str ( "Screw size " , diam , " unsupported for head type \"" , head , "\"" ) ) ,
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driveind = small && drive = = "phillips" || ! small && drive = = "hex" ? 1 :
drive = = "torx" ? 2 :
undef ,
drive_dims = small ? (
drive = = "phillips" && ! undercut ? [ [ "drive_diameter" , INCH * entry [ 4 ] ] ,
[ "drive_width" , INCH * entry [ 6 ] ] , [ "drive_depth" , INCH * entry [ 5 ] ] ] :
drive = = "phillips" && undercut ? [ [ "drive_diameter" , INCH * entry [ 9 ] ] ,
[ "drive_width" , INCH * entry [ 11 ] ] , [ "drive_depth" , INCH * entry [ 10 ] ] ] :
drive = = "slot" && ! undercut ? [ [ "drive_width" , INCH * entry [ 7 ] ] , [ "drive_depth" , INCH * entry [ 8 ] ] ] :
drive = = "slot" && undercut ? [ [ "drive_width" , INCH * entry [ 7 ] ] , [ "drive_depth" , INCH * entry [ 12 ] ] ] :
[ ]
)
:
(
drive = = "hex" ? [ [ "drive_depth" , INCH * entry [ 3 ] ] ] :
drive = = "torx" ? [ [ "drive_depth" , INCH * entry [ 4 ] ] ] : [ ]
)
)
concat ( [ [ "head" , "flat" ] , [ "head_angle" , 82 ] , [ "head_size" , INCH * entry [ 0 ] ] ] ,
is_def ( driveind ) ? [ [ "drive_size" , ( drive = = "hex" ? INCH : 1 ) * entry [ driveind ] ] ] : [ ] ,
undercut ? [ [ "head_height" , INCH * entry [ 3 ] ] ] : [ ] , drive_dims
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)
: [ ]
)
concat ( [ [ "system" , "UTS" ] , [ "diameter" , INCH * diameter ] , [ "pitch" , pitch ] , [ "drive" , drive ] ] ,
head_data
) ;
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function _screw_info_metric ( diam , pitch , head , thread , drive ) =
let (
pitch = is_num ( thread ) ? thread :
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thread = = "none" ? 0 :
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is_def ( pitch ) ? pitch :
let (
tind = struct_val ( [ [ "coarse" , 0 ] ,
[ "fine" , 1 ] ,
[ "extra fine" , 2 ] , [ "extrafine" , 2 ] ,
[ "super fine" , 3 ] , [ "superfine" , 3 ] ] ,
downcase ( thread ) ) ,
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dummy = assert ( is_def ( tind ) , str ( "Unknown thread type, \"" , thread , "\"" ) ) ,
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// coarse fine xfine superfine
ISO_thread = [
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[ 1 , [ 0.25 , 0.2 , undef , undef , ] ] ,
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[ 1.2 , [ 0.25 , 0.2 , undef , undef , ] ] ,
[ 1.4 , [ 0.3 , 0.2 , undef , undef , ] ] ,
[ 1.6 , [ 0.35 , 0.2 , undef , undef , ] ] ,
[ 1.7 , [ 0.35 , undef , undef , undef , ] ] ,
[ 1.8 , [ 0.35 , 0.2 , undef , undef , ] ] ,
[ 2 , [ 0.4 , 0.25 , undef , undef , ] ] ,
[ 2.2 , [ 0.45 , 0.25 , undef , undef , ] ] ,
[ 2.3 , [ 0.4 , undef , undef , undef , ] ] ,
[ 2.5 , [ 0.45 , 0.35 , undef , undef , ] ] ,
[ 2.6 , [ 0.45 , undef , undef , undef , ] ] ,
[ 3 , [ 0.5 , 0.35 , undef , undef , ] ] ,
[ 3.5 , [ 0.6 , 0.35 , undef , undef , ] ] ,
[ 4 , [ 0.7 , 0.5 , undef , undef , ] ] ,
[ 5 , [ 0.8 , 0.5 , undef , undef , ] ] ,
[ 6 , [ 1 , 0.75 , undef , undef , ] ] ,
[ 7 , [ 1 , 0.75 , undef , undef , ] ] ,
[ 8 , [ 1.25 , 1 , 0.75 , undef , ] ] ,
[ 9 , [ 1.25 , 1 , 0.75 , undef , ] ] ,
[ 10 , [ 1.5 , 1.25 , 1 , 0.75 , ] ] ,
[ 11 , [ 1.5 , 1 , 0.75 , undef , ] ] ,
[ 12 , [ 1.75 , 1.5 , 1.25 , 1 , ] ] ,
[ 14 , [ 2 , 1.5 , 1.25 , 1 , ] ] ,
[ 16 , [ 2 , 1.5 , 1 , undef , ] ] ,
[ 18 , [ 2.5 , 2 , 1.5 , 1 , ] ] ,
[ 20 , [ 2.5 , 2 , 1.5 , 1 , ] ] ,
[ 22 , [ 2.5 , 2 , 1.5 , 1 , ] ] ,
[ 24 , [ 3 , 2 , 1.5 , 1 , ] ] ,
[ 27 , [ 3 , 2 , 1.5 , 1 , ] ] ,
[ 30 , [ 3.5 , 3 , 2 , 1.5 , ] ] ,
[ 33 , [ 3.5 , 3 , 2 , 1.5 , ] ] ,
[ 36 , [ 4 , 3 , 2 , 1.5 , ] ] ,
[ 39 , [ 4 , 3 , 2 , 1.5 , ] ] ,
[ 42 , [ 4.5 , 4 , 3 , 2 , ] ] ,
[ 45 , [ 4.5 , 4 , 3 , 2 , ] ] ,
[ 48 , [ 5 , 4 , 3 , 2 , ] ] ,
[ 52 , [ 5 , 4 , 3 , 2 , ] ] ,
[ 56 , [ 5.5 , 4 , 3 , 2 , ] ] ,
[ 60 , [ 5.5 , 4 , 3 , 2 , ] ] ,
[ 64 , [ 6 , 4 , 3 , 2 , ] ] ,
[ 68 , [ 6 , 4 , 3 , 2 , ] ] ,
[ 72 , [ 6 , 4 , 3 , 2 , ] ] ,
[ 80 , [ 6 , 4 , 3 , 2 , ] ] ,
[ 90 , [ 6 , 4 , 3 , 2 , ] ] ,
[ 100 , [ 6 , 4 , 3 , 2 , ] ] ,
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] ,
tentry = struct_val ( ISO_thread , diam )
)
assert ( is_def ( tentry ) , str ( "Unknown screw size, M" , diam , "" ) )
tentry [ tind ] ,
head_data =
head = = "none" ? let (
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metric_setscrew =
[
[ 1.4 , [ 0.7 ] ] ,
[ 1.6 , [ 0.7 ] ] ,
[ 1.8 , [ 0.7 ] ] ,
[ 2 , [ 0.9 ] ] ,
[ 2.5 , [ 1.3 ] ] ,
[ 3 , [ 1.5 , 6 , 0.77 ] ] ,
[ 4 , [ 2 , 8 , 1.05 ] ] ,
[ 5 , [ 2.5 , 10 , 1.24 ] ] ,
[ 6 , [ 3 , 15 , 1.74 ] ] ,
[ 8 , [ 4 , 25 , 2.24 ] ] ,
[ 10 , [ 5 , 40 , 2.97 ] ] ,
[ 12 , [ 6 , 45 , 3.48 ] ] ,
[ 16 , [ 8 , 55 , 5.15 ] ] ,
[ 20 , [ 10 , undef , undef ] ] ,
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] ,
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entry = struct_val ( metric_setscrew , diam ) ,
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dummy = assert ( is_def ( entry ) , str ( "Screw size M" , diam , " unsupported for headless screws" ) ) ,
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drive_dim = drive = = "hex" ? [ [ "drive_size" , entry [ 0 ] ] , [ "drive_depth" , diam / 2 ] ] :
drive = = "torx" ? [ [ "drive_size" , entry [ 1 ] ] , [ "drive_depth" , entry [ 2 ] ] ] : [ ]
)
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concat ( [ [ "head" , "none" ] ] , drive_dim )
: head = = "hex" ? let (
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metric_hex = [
// flat to flat width, height
[ 5 , [ 8 , 3.5 ] ] ,
[ 6 , [ 10 , 4 ] ] ,
[ 8 , [ 13 , 5.3 ] ] ,
[ 10 , [ 17 , 6.4 ] ] ,
[ 12 , [ 19 , 7.5 ] ] ,
[ 14 , [ 22 , 8.8 ] ] ,
[ 16 , [ 24 , 10 ] ] ,
[ 18 , [ 27 , 11.5 ] ] ,
[ 20 , [ 30 , 12.5 ] ] ,
[ 24 , [ 36 , 15 ] ] ,
[ 30 , [ 46 , 18.7 ] ] ,
] ,
entry = struct_val ( metric_hex , diam )
)
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assert ( is_def ( entry ) , str ( "Screw size M" , diam , " unsupported for head type \"" , head , "\"" ) )
[ [ "head" , "hex" ] , [ "head_size" , entry [ 0 ] ] , [ "head_height" , entry [ 1 ] ] ]
: in_list ( head , [ "socket" , "socket ribbed" ] ) ? let (
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// ISO 14579 gives dimensions for Torx (hexalobular) socket heads
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metric_socket = [ // height = screw diameter
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//diam, hex, torx size, torx depth
[ 1.4 , [ 2.5 , 1.3 ] ] ,
[ 1.6 , [ 3 , 1.5 ] ] ,
[ 2 , [ 3.8 , 1.5 , 6 , 0.775 ] ] ,
[ 2.5 , [ 4.5 , 2 , 8 , 0.975 ] ] ,
[ 2.6 , [ 5 , 2 , 8 , 1.05 ] ] ,
[ 3 , [ 5.5 , 2.5 , 10 , 1.14 ] ] ,
[ 3.5 , [ 6.2 , 2.5 ] ] ,
[ 4 , [ 7 , 3 , 25 , 1.61 ] ] ,
[ 5 , [ 8.5 , 4 , 27 , 1.84 ] ] ,
[ 6 , [ 10 , 5 , 30 , 2.22 ] ] ,
[ 7 , [ 12 , 6 ] ] ,
[ 8 , [ 13 , 6 , 45 , 3.115 ] ] ,
[ 10 , [ 16 , 8 , 50 , 3.82 ] ] ,
[ 12 , [ 18 , 10 , 55 , 5.015 ] ] ,
[ 14 , [ 21 , 12 , 60 , 5.805 ] ] ,
[ 16 , [ 24 , 14 , 70 , 6.815 ] ] ,
[ 18 , [ 27 , 14 , 80 , 7.75 ] ] ,
[ 20 , [ 30 , 17 , 90 , 8.945 ] ] ,
[ 22 , [ 33 , 17 ] ] ,
[ 24 , [ 36 , 19 , 100 , 10.79 ] ] ,
[ 27 , [ 40 , 19 ] ] ,
[ 30 , [ 45 , 22 ] ] ,
[ 33 , [ 50 , 24 ] ] ,
[ 36 , [ 54 , 27 ] ] ,
[ 42 , [ 63 , 32 ] ] ,
[ 48 , [ 72 , 36 ] ] ,
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] ,
entry = struct_val ( metric_socket , diam ) ,
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dummy = assert ( is_def ( entry ) , str ( "Screw size M" , diam , " unsupported for headless screws" ) ) ,
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drive_size = drive = = "hex" ? [ [ "drive_size" , entry [ 1 ] ] , [ "drive_depth" , diam / 2 ] ] :
drive = = "torx" ? [ [ "drive_size" , entry [ 2 ] ] , [ "drive_depth" , entry [ 3 ] ] ] :
[ ]
)
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concat ( [ [ "head" , head ] , [ "head_size" , entry [ 0 ] ] , [ "head_height" , diam ] ] , drive_size )
: in_list ( head , [ "pan" , "pan round" , "pan flat" ] ) ? let (
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metric_pan = [ // pan head for phillips or slotted, torx from ISO 14583
// head height
// diam, slotted phillips phillips size phillips diam, phillips depth, ph width, slot width,slot depth, torx size, torx depth
[ 1.6 , [ 3.2 , 1 , 1.3 , 0 , undef , undef , undef , 0.4 , 0.35 ] ] ,
[ 2 , [ 4 , 1.3 , 1.6 , 1 , 1.82 , 1.19 , 0.48 , 0.5 , 0.5 , 6 , 0.7 ] ] ,
[ 2.5 , [ 5 , 1.5 , 2 , 1 , 2.68 , 1.53 , 0.70 , 0.6 , 0.6 , 8 , 0.975 ] ] ,
[ 3 , [ 5.6 , 1.8 , 2.4 , 1 , 2.90 , 1.76 , 0.74 , 0.8 , 0.7 , 10 , 1.14 ] ] ,
[ 3.5 , [ 7 , 2.1 , 3.1 , 2 , 3.92 , 1.95 , 0.87 , 1.0 , 0.8 , 15 , 1.2 ] ] ,
[ 4 , [ 8 , 2.4 , 3.1 , 2 , 4.40 , 2.45 , 0.93 , 1.2 , 1.0 , 20 , 1.465 ] ] ,
[ 5 , [ 9.5 , 3 , 3.8 , 2 , 4.90 , 2.95 , 1.00 , 1.2 , 1.2 , 25 , 1.715 ] ] ,
[ 6 , [ 12 , 3.6 , 4.6 , 3 , 6.92 , 3.81 , 1.14 , 1.6 , 1.4 , 30 , 2.22 ] ] ,
[ 8 , [ 16 , 4.8 , 6 , 4 , 9.02 , 4.88 , 1.69 , 2.0 , 1.9 , 45 , 2.985 ] ] ,
[ 10 , [ 20 , 6.0 , 7.5 , 4 , 10.18 , 5.09 , 1.84 , 2.5 , 2.4 , 50 , 3.82 ] ] ,
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] ,
type = head = = "pan" ? ( drive = = "slot" ? "pan flat" : "pan round" ) : head ,
htind = drive = = "slot" ? 1 : 2 ,
entry = struct_val ( metric_pan , diam ) ,
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dummy = assert ( is_def ( entry ) , str ( "Screw size M" , diam , " unsupported for headless screws" ) ) ,
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drive_size = drive = = "phillips" ? [ [ "drive_size" , entry [ 3 ] ] , [ "drive_diameter" , entry [ 4 ] ] , [ "drive_depth" , entry [ 5 ] ] , [ "drive_width" , entry [ 6 ] ] ]
: drive = = "torx" ? [ [ "drive_size" , entry [ 9 ] ] , [ "drive_depth" , entry [ 10 ] ] ]
: drive = = "slot" ? [ [ "drive_width" , entry [ 7 ] ] , [ "drive_depth" , entry [ 8 ] ] ]
: [ ]
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)
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concat ( [ [ "head" , type ] , [ "head_size" , entry [ 0 ] ] , [ "head_height" , entry [ htind ] ] ] , drive_size )
: head = = "button" || head = = "cheese" ? let (
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// hex drive depth from ISO 7380-1
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metric_button = [ // button, hex drive
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// head diam, height, hex, phillips, hex drive depth, torx size, torx depth
[ 1.6 , [ 2.9 , 0.8 , 0.9 , undef , 0.55 ] ] , // These four cases,
[ 2 , [ 3.5 , 1.3 , 1.3 , undef , 0.69 ] ] , // extrapolated hex depth
[ 2.2 , [ 3.8 , 0.9 , 1.3 , undef , 0.76 ] ] , //
[ 2.5 , [ 4.6 , 1.5 , 1.5 , undef , 0.87 ] ] , //
[ 3 , [ 5.7 , 1.65 , 2 , undef , 1.04 , 8 , 0.81 ] ] ,
[ 3.5 , [ 5.7 , 1.65 , 2 , undef , 1.21 ] ] , // interpolated hex depth
[ 4 , [ 7.6 , 2.2 , 2.5 , undef , 1.30 , 15 , 1.3 ] ] ,
[ 5 , [ 9.5 , 2.75 , 3 , undef , 1.56 , 25 , 1.56 ] ] ,
[ 6 , [ 10.5 , 3.3 , 4 , undef , 2.08 , 27 , 2.08 ] ] ,
[ 8 , [ 14 , 4.4 , 5 , undef , 2.60 , 40 , 2.3 ] ] ,
[ 10 , [ 17.5 , 5.5 , 6 , undef , 3.12 , 45 , 2.69 ] ] ,
[ 12 , [ 21 , 6.6 , 8 , undef , 4.16 , 55 , 4.02 ] ] ,
[ 16 , [ 28 , 8.8 , 10 , undef , 5.2 ] ] ,
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] ,
metric_cheese = [ // slotted, phillips ISO 1207, ISO 7048
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// hex drive is not supported (hence undefs)
// head diam, head height, hex drive, phillips drive, slot width, slot depth, ph diam
[ 1 , [ 2 , 0.7 , undef , undef ] ] ,
[ 1.2 , [ 2.3 , 0.8 , undef , undef ] ] ,
[ 1.4 , [ 2.6 , 0.9 , undef , undef ] ] ,
[ 1.6 , [ 3 , 1 , undef , undef , 0.4 , 0.45 ] ] ,
[ 2 , [ 3.8 , 1.3 , undef , 1 , 0.5 , 0.6 , undef , undef ] ] ,
[ 2.5 , [ 4.5 , 1.6 , undef , 1 , 0.6 , 0.7 , 2.7 , 1.20 ] ] ,
[ 3 , [ 5.5 , 2 , undef , 2 , 0.8 , 0.85 , 3.5 , 0.86 ] ] ,
[ 3.5 , [ 6 , 2.4 , undef , 2 , 1.0 , 1.0 , 3.8 , 1.15 ] ] ,
[ 4 , [ 7 , 2.6 , undef , 2 , 1.2 , 1.1 , 4.1 , 1.45 ] ] ,
[ 5 , [ 8.5 , 3.3 , undef , 2 , 1.2 , 1.3 , 4.8 , 2.14 ] ] ,
[ 6 , [ 10 , 3.9 , undef , 3 , 1.6 , 1.6 , 6.2 , 2.25 ] ] ,
[ 8 , [ 13 , 5 , undef , 3 , 2.0 , 2.0 , 7.7 , 3.73 ] ] ,
[ 10 , [ 16 , 6 , undef , undef , 2.5 , 2.4 , undef , undef ] ]
] ,
metric_cheese_torx = [ // torx cheese, ISO 14580, the heads are taller than other cheese screws
//head diam, head height, torx size, torx depth
[ 2 , [ 3.8 , 1.55 , 6 , 0.775 ] ] ,
[ 2.5 , [ 4.5 , 1.85 , 8 , 0.845 ] ] ,
[ 3 , [ 5.5 , 2.4 , 10 , 1.14 ] ] ,
[ 3.5 , [ 6 , 2.6 , 15 , 1.2 ] ] ,
[ 4 , [ 7 , 3.1 , 20 , 1.465 ] ] ,
[ 5 , [ 8.5 , 3.65 , 25 , 1.715 ] ] ,
[ 6 , [ 10 , 4.4 , 30 , 2.095 ] ] ,
[ 8 , [ 13 , 5.8 , 45 , 2.855 ] ] ,
[ 10 , [ 16 , 6.9 , 59 , 3.235 ] ]
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] ,
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entry = struct_val ( head = = "button" ? metric_button
: drive = = "torx" ? metric_cheese_torx
: metric_cheese ,
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diam ) ,
dummy = assert ( is_def ( entry ) , str ( "Screw size M" , diam , " unsupported for headless screws" ) ) ,
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drive_index = drive = = "phillips" ? 3
: drive = = "hex" ? 2
: undef ,
drive_dim = head = = "button" && drive = = "hex" ? [ [ "drive_depth" , entry [ 4 ] ] ]
: head = = "button" && drive = = "torx" ? [ [ "drive_size" , entry [ 5 ] ] , [ "drive_depth" , entry [ 6 ] ] ]
: head = = "cheese" && drive = = "torx" ? [ [ "drive_size" , entry [ 2 ] ] , [ "drive_depth" , entry [ 3 ] ] ]
: head = = "cheese" && drive = = "slot" ? [ [ "drive_width" , entry [ 4 ] ] , [ "drive_depth" , entry [ 5 ] ] ]
: head = = "cheese" && drive = = "phillips" ? [ [ "drive_diameter" , entry [ 6 ] ] , [ "drive_depth" , entry [ 7 ] ] ,
[ "drive_width" , entry [ 6 ] / 4 ] ] // Fabricated this width value to fill in missing field
: [ ] ,
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drive_size = is_def ( drive_index ) ? [ [ "drive_size" , entry [ drive_index ] ] ] : [ ]
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)
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concat ( [ [ "head" , head ] , [ "head_size" , entry [ 0 ] ] , [ "head_height" , entry [ 1 ] ] ] , drive_size , drive_dim )
: in_list ( head , [ "flat" , "flat small" , "flat large" ] ) ? let (
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small = head = = "flat small" || ( head = = "flat" && ( drive ! = "hex" && drive ! = "torx" ) ) ,
metric_flat_large = [ // for hex drive
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// diam hex size hex depth torx torx depth
[ 2 , [ 4 , 1.3 , undef ] ] ,
[ 2.5 , [ 5 , 1.5 , undef ] ] ,
[ 3 , [ 6 , 2 , 1.1 , 10 , 0.96 ] ] ,
[ 4 , [ 8.25 , 2.5 , 1.5 , 20 , 1.34 ] ] ,
[ 5 , [ 10 , 3 , 1.9 , 25 , 1.54 ] ] ,
[ 6 , [ 12.5 , 4 , 2.2 , 30 , 1.91 ] ] ,
[ 8 , [ 16.5 , 5 , 3.0 , 40 , 2.3 ] ] ,
[ 10 , [ 21 , 6 , 3.6 , 50 , 3.04 ] ] ,
[ 12 , [ 25 , 8 , 4.3 ] ] ,
[ 14 , [ 28.5 , 10 , 4.5 ] ] ,
[ 16 , [ 31 , 10 , 4.8 ] ] ,
[ 18 , [ 33 , 12 , undef ] ] ,
[ 20 , [ 38 , 12 , 5.6 ] ]
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] ,
metric_flat_small = [ // for phillips, slotted
// Phillips from ASME B18.6.7M (ISO 7046 gives different values),
// Slots from ISO 2009/DIN 963, which gives more values than ASME (and also inconsistent)
// diam, ph size, ph diam, ph depth, ph width, slot width, slot depth
[ 1.6 , [ 3 , 0 , undef , undef , undef , 0.4 , 0.32 ] ] ,
[ 2 , [ 3.8 , 0 , 2.14 , 1.54 , 0.53 , 0.5 , 0.4 ] ] ,
[ 2.5 , [ 4.7 , 1 , 2.80 , 1.78 , 0.74 , 0.6 , 0.5 ] ] ,
[ 2.6 , [ 4.7 , 1 , 2.80 , 1.78 , 0.74 , 0.6 , 0.5 ] ] ,
[ 3 , [ 5.6 , 1 , 3.10 , 2.08 , 0.79 , 0.8 , 0.6 ] ] ,
[ 3.5 , [ 6.5 , 1 , 4.06 , 2.25 , 0.91 , 0.8 , 0.7 ] ] ,
[ 4 , [ 7.5 , 2 , 4.46 , 2.65 , 0.96 , 1.0 , 0.8 ] ] ,
[ 5 , [ 9.2 , 2 , 5.06 , 3.25 , 1.04 , 1.2 , 1.0 ] ] ,
[ 6 , [ 11 , 3 , 6.62 , 3.61 , 1.12 , 1.6 , 1.2 ] ] ,
[ 8 , [ 14.5 , 4 , 8.78 , 4.88 , 1.80 , 2.0 , 1.6 ] ] ,
[ 10 , [ 18 , undef , undef , undef , undef , 2.5 , 2 ] ] ,
[ 12 , [ 22 , undef , undef , undef , undef , 3 , 2.4 ] ] ,
[ 14 , [ 25 , undef , undef , undef , undef , 3 , 2.8 ] ] ,
[ 16 , [ 29 , undef , undef , undef , undef , 4 , 3.2 ] ] ,
[ 18 , [ 33 , undef , undef , undef , undef , 4 , 3.6 ] ] ,
[ 20 , [ 36 , undef , undef , undef , undef , 5 , 4 ] ] ,
] ,
entry = struct_val ( small ? metric_flat_small : metric_flat_large , diam ) ,
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dummy = assert ( is_def ( entry ) , str ( "Screw size M" , diam , " unsupported for headless screws" ) ) ,
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driveind = small && drive = = "phillips" || ! small && drive = = "hex" ? 1 : ! small && drive = = "torx" ? 3 : undef ,
drive_dim = small && drive = = "phillips" ? [ [ "drive_diameter" , entry [ 2 ] ] , [ "drive_depth" , entry [ 3 ] ] , [ "drive_width" , entry [ 4 ] ] ] :
small && drive = = "slot" ? [ [ "drive_width" , entry [ 5 ] ] , [ "drive_depth" , entry [ 6 ] ] ] :
! small && drive = = "torx" ? [ [ "drive_size" , entry [ 3 ] ] , [ "drive_depth" , entry [ 4 ] ] ] :
! small && drive = = "hex" ? [ [ "drive_depth" , entry [ 2 ] ] ] : [ ]
)
concat ( [ [ "head" , "flat" ] , [ "head_angle" , 90 ] , [ "head_size" , entry [ 0 ] ] ] ,
is_def ( driveind ) ? [ [ "drive_size" , entry [ driveind ] ] ] : [ ] ,
drive_dim
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)
: [ ]
)
concat (
[ [ "system" , "ISO" ] , [ "diameter" , diam ] , [ "pitch" , pitch ] , [ "drive" , drive ] ] ,
head_data
) ;
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function _is_positive ( x ) = is_num ( x ) && x > 0 ;
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function _validate_screw_spec ( spec ) = let (
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dummy = echo_struct ( spec , "Screw Specification" ) ,
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systemOK = in_list ( struct_val ( spec , "system" ) , [ "UTS" , "ISO" ] ) ,
diamOK = _is_positive ( struct_val ( spec , "diameter" ) ) ,
pitch = struct_val ( spec , "pitch" ) ,
pitchOK = is_undef ( pitch ) || ( is_num ( pitch ) && pitch >= 0 ) ,
head = struct_val ( spec , "head" ) ,
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headOK = head = = "none" || (
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in_list ( head , [ "cheese" , "pan flat" , "pan round" , "flat" , "flat large" , "flat small" , "flat undercut" , "button" , "socket" , "socket ribbed" , "fillister" , "round" , "hex" ] ) &&
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_is_positive ( struct_val ( spec , "head_size" ) ) ) ,
drive = struct_val ( spec , "drive" ) ,
driveOK = is_undef ( drive ) || drive = = "none"
|| (
_is_positive ( struct_val ( spec , "drive_depth" ) ) &&
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(
in_list ( drive , [ "torx" , "hex" ] )
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|| ( drive = = "phillips" && _is_positive ( struct_val ( spec , "drive_diameter" ) ) &&
_is_positive ( struct_val ( spec , "drive_width" ) ) &&
_is_positive ( struct_val ( spec , "drive_width" ) ) )
|| ( drive = = "slot" && _is_positive ( struct_val ( spec , "drive_width" ) ) )
)
)
)
assert ( systemOK , str ( "Screw spec has invalid \"system\", " , struct_val ( spec , "system" ) , ". Must be \"ISO\" or \"UTS\"" ) )
assert ( diamOK , str ( "Screw spec has invalid \"diameter\", " , struct_val ( spec , "diameter" ) ) )
assert ( pitchOK , str ( "Screw spec has invalid \"pitch\", " , pitch ) )
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assert ( headOK , str ( "Screw head type invalid or unknown for your screw type and size" ) ) // head is "undef" for invalid heads; we don't know what the user specified
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assert ( driveOK , str ( "Screw drive type \"" , drive , "\" invalid or unknown for your screw size or head type, \"" , head , "\"" ) )
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spec ;
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// Function: thread_specification()
// Usage:
// thread_specification(screw_spec, [tolerance], [internal])
// Description:
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// Determines actual thread geometry for a given screw with specified tolerance and nominal size. See [tolerance](#subsection-tolerance) for
// information on tolerances. If tolerance is omitted the default is used. If tolerance
// is "none" or 0 then return the nominal thread geometry. When `internal=true` the nut tolerance is used.
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// .
// The return value is a structure with the following fields:
// - pitch: the thread pitch
// - d_major: major diameter range
// - d_pitch: pitch diameter range
// - d_minor: minor diameter range
// - basic: vector `[minor, pitch, major]` of the nominal or "basic" diameters for the threads
// Arguments:
// screw_spec = screw specification structure
// ---
// tolerance = thread geometry tolerance
// internal = true for internal threads. Default: false
function thread_specification ( screw_spec , tolerance = undef , internal = false ) =
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let (
diam = struct_val ( screw_spec , "diameter" ) ,
pitch = struct_val ( screw_spec , "pitch" ) ,
tspec = tolerance = = 0 || tolerance = = "none" ? _exact_thread_tolerance ( diam , pitch )
: struct_val ( screw_spec , "system" ) = = "ISO" ? _ISO_thread_tolerance ( diam , pitch , internal , tolerance )
: struct_val ( screw_spec , "system" ) = = "UTS" ? _UTS_thread_tolerance ( diam , pitch , internal , tolerance )
: assert ( false , "Unknown screw system " , struct_val ( screw_spec , "system" ) )
)
assert ( min ( struct_val ( tspec , "d_minor" ) ) > 0 , "Thread specification is too coarse for the diameter" )
tspec ;
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// recess sizing:
// http://www.fasnetdirect.com/refguide/Machinepancombo.pdf
//
/* ASME B 18.6.3
http : //www.smithfast.com/newproducts/screws/msflathead/
/* phillips recess diagram
http : //files.engineering.com/getfile.aspx?folder=76fb0d5e-1fff-4c49-87a5-05979477ca88&file=Noname.jpg&__hstc=212727627.6c577ef84c12d9cc69c819eea7be49d2.1563972499721.1563972499721.1563972499721.1&__hssc=212727627.1.1563972499721&__hsfp=165344926
* /
// To do list
//
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// Is there no way to create a mask for making threaded holes? This seems to be missing.
//
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// Metric hex engagement:
// https://www.bayoucitybolt.com/socket-head-cap-screws-metric.html
//
// Torx drive depth for UTS and ISO (at least missing for "flat small", which means you can't select torx for this head type)
// Handle generic phillips (e.g. ph2) or remove it?
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// https://www.fasteners.eu/tech-info/ISO/7721-2/
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//
// How do you insert a threaded hole into a model?
// Default nut thickness
//
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// JIS
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//https://www.garagejournal.com/forum/media/jis-b-4633-vs-iso-8764-1-din-5260-ph.84492/
//square:
//https://www.aspenfasteners.com/content/pdf/square_drive_specification.pdf
//http://www.globalfastener.com/standards/index.php?narr58=149
//https://patents.google.com/patent/US1003657
// thread standards:
// https://www.gewinde-normen.de/en/index.html
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///////////////////////////////////////////////////////
//
// how to make screw mask: examples (e.g. for clearance hole w/ countersink)
// how to make a screw hole (a mask function?)
//
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// vim: expandtab tabstop=4 shiftwidth=4 softtabstop=4 nowrap
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/* Table of common shoulder sizes
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[ "#0" , 0.0615 ( . - 002 to 0 )
[ "#1" , 3 / 32
[ "#2" , 3 / 32
[ "#3" , 1 / 8
[ "#4" , 1 / 8
[ "#5" , 5 / 32
[ "#6" , 5 / 32
[ "#8" , 3 / 16
[ "#10" , 1 / 4
[ "#12" ,
[ 1 / 4 , 5 / 16 . 004
[ 5 / 16 , 3 / 8
[ 3 / 8 , 1 / 2 . 004
[ 7 / 16 ,
[ 1 / 2 , 5 / 8
[ 9 / 16 ,
[ 5 / 8 , 3 / 4
[ 3 / 4 , 1
[ 7 / 8 , 1 1 / 4
[ 1 , 1 1 / 2
[ 1.125 , 1 1 / 2
[ 1.25 ,
[ 1.375 ,
[ 1.5 ,
[ 1.75 ,
[ 2 ,
[ 1 ,
[ 1.2 ,
[ 1.4 ,
[ 1.6 , 2 . 072 to . 01 tol
[ 1.7 ,
[ 1.8 ,
[ 2 , 3
[ 2.2 ,
[ 2.3 ,
[ 2.5 ,
[ 2.6 ,
[ 3 , 4
[ 3.5 ,
[ 4 , 5
[ 5 , 6 ( or 6.5 )
[ 6 , 8
[ 7 ,
[ 8 , 10
[ 9 ,
[ 10 , 12 or 13
[ 11 ,
[ 12 , 16
[ 14 ,
[ 16 , 20
[ 18 ,
[ 20 , 24
[ 22 ,
[ 24 ,
[ 27 ,
[ 30 ,
[ 33 ,
[ 36 ,
[ 39 ,
[ 42 ,
[ 45 ,
[ 48 ,
[ 52 ,
[ 56 ,
[ 60 ,
[ 64 ,
[ 68 ,
[ 72 ,
[ 80 ,
[ 90 ,
[ 100 ,
* /
/*
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. 1375 s + . 325 to give length of chamfer on flatheads , s = diam
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ISO 10642 / DIN 7991 for hex head
ISO 14581 for torx
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TODO list :
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square drive
proper edge on flatheads
need to make holes at actual size instead of nominal ?
anchoring : "headtop" "headbot" "shaftbot" "shafttop" , top of counterbore same as top of head ?
oversize different for head than shaft
heads on shoulder screws
torx depth for UTS pan head
$fn control
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* /
