diff --git a/drawing.scad b/drawing.scad
index 7124732..7d4bb76 100644
--- a/drawing.scad
+++ b/drawing.scad
@@ -372,20 +372,16 @@ module stroke(
                                   : zrot(joint_angle);
                                 multmatrix(mat) polygon(joint_shape);
                             } else {
+                                // These are parallel to the path
                                 v1 = path2[i] - path2[i-1];
                                 v2 = path2[i+1] - path2[i];
                                 ang = modang(v_theta(v2) - v_theta(v1));
-                                pv1 = rot(-90, p=unit(v1,BACK));
-                                pv2 = rot(-90, p=unit(v2,BACK));
-                                if (!approx(ang,0)) {
-                                    if (ang>=0) {
-                                        rot(from=RIGHT, to=pv1)
-                                            arc(d=widths[i], angle=ang, wedge=true);
-                                    } else {
-                                        rot(from=RIGHT, to=-pv2)
-                                            arc(d=widths[i], angle=-ang, wedge=true);
-                                    }
-                                }
+                                // Need 90 deg offset to make wedge perpendicular to path, and the wedge
+                                // position depends on whether we turn left (ang<0) or right (ang>0)
+                                theta = v_theta(v1) - sign(ang)*90;
+                                ang_eps = 0.1;
+                                if (!approx(ang,0))
+                                  arc(d=widths[i], angle=[theta-ang_eps, theta+ang+ang_eps], wedge=true);
                             }
                         }
                     }
diff --git a/screws.scad b/screws.scad
index 2cc3f09..b78bd92 100644
--- a/screws.scad
+++ b/screws.scad
@@ -76,7 +76,7 @@ include <screw_drive.scad>
 //    .
 //    |ISO|UTS|Head            | Drive  |
 //    |---|---|--------------- | ----------------------------|
-//    |X|X|"none"          | hex, torx, slot (UTS only)|
+//    |X|X|"none"          | hex, torx, slot |
 //    |X|X|"hex"           | *none*|
 //    |X|X|"socket"        | hex, torx|
 //    |X|X|"button"        | hex, torx|
@@ -1263,7 +1263,7 @@ function _screw_info_english(diam, threadcount, head, thread, drive) =
                ["#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
+               ["#4", [  0.183,  3/32, 10,        0.051,      0.049]],   // half the screw 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]],
@@ -2088,3 +2088,61 @@ $fn control
 
 */
 
+/*
+
+
+iso shoulder screws, hex drive socket head  ISO 7379
+  Mcmaster has variations like 12mm shoulder for m10, 6mm shoulder for M5
+
+   shld  thread  head  head  hex  hex dep
+   diam  length  diam   ht                   shold tol
+5, [6.5,    9.5,  10,  4.5,   3,  2.4         .03
+6, [8  ,    11 ,  13,  5.5,   4,  3.3         .03
+8, [10 ,    13 ,  16,  7  ,   5,  4.2         .03 
+10,[13 ,    16 ,  18,  9  ,   6,  4.9         .037
+12,[16 ,    18 ,  24, 11  ,   8,  6.6         .037
+16,[20 ,    22 ,  30, 14  ,  10,  8.8         .046
+20,[25 ,    27 ,  36, 16  ,  12,  10          .046
+
+
+UTS shoulder screws, b18.3 (table 13)
+
+       sh diam  thread len, head diam   hex size  hex depth
+[#4,    [1/8  ,   5/32 ,    1/4      ,  5/64   ,  0.067
+[#6,    [5/32 ,   3/16 ,    9/32     ,  3/32   ,  0.067
+[#8,    [3/16 ,   3/16 ,    5/16     ,  3/32   ,  0.079
+[#10,   [1/4  ,   3/8  ,    3/8      ,  1/8    ,  0.094
+[1/4,   [5/16 ,   7/16 ,    7/16     ,  5/32   ,  0.117
+[5/16,  [3/8  ,   1/2  ,    9/16     ,  3/16   ,  0.141
+[3/8,   [1/2  ,   5/8  ,    3/4      ,  1/4    ,  0.188
+[1/2,   [5/8  ,   3/4  ,    7/8      ,  5/16   ,  0.234
+[5/8,   [3/4  ,   7/8  ,    1        ,  3/8    ,  0.281
+[3/4,   [1    ,   1    ,    1+5/16   ,  1/2    ,  0.375
+[7/8,   [1+1/4,   1+1/8,    1+3/4    ,  5/8    ,  0.469
+[1+1/8, [1+1/2,   1+1/2,    2+1/8    ,  7/8    ,  0.656
+[1+1/4, [1+3/4,   1+3/4,    2+3/8    ,  1      ,  0.750
+[1+1/2, [2    ,   2    ,    2+3/4    ,  1+1/4  ,  0.937
+
+         shoulder tol = .003
+
+height = .5 (shoulder nom diam) + .0625
+         .5 (shoulder nom diam) + .125  >= 3/4
+
+         
+*/
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+,