diff --git a/tests/test_torx_drive.scad b/tests/test_torx_drive.scad
new file mode 100644
index 0000000..7c4bcf2
--- /dev/null
+++ b/tests/test_torx_drive.scad
@@ -0,0 +1,61 @@
+include <../std.scad>
+include <../torx_drive.scad>
+
+
+module test_torx_outer_diam() {
+    assert_approx(torx_outer_diam(10), 2.80);
+    assert_approx(torx_outer_diam(15), 3.35);
+    assert_approx(torx_outer_diam(20), 3.95);
+    assert_approx(torx_outer_diam(25), 4.50);
+    assert_approx(torx_outer_diam(30), 5.60);
+    assert_approx(torx_outer_diam(40), 6.75);
+}
+test_torx_outer_diam();
+
+
+module test_torx_inner_diam() {
+    assert_approx(torx_inner_diam(10), 2.05);
+    assert_approx(torx_inner_diam(15), 2.40);
+    assert_approx(torx_inner_diam(20), 2.85);
+    assert_approx(torx_inner_diam(25), 3.25);
+    assert_approx(torx_inner_diam(30), 4.05);
+    assert_approx(torx_inner_diam(40), 4.85);
+}
+test_torx_inner_diam();
+
+
+module test_torx_depth() {
+    assert_approx(torx_depth(10), 3.56);
+    assert_approx(torx_depth(15), 3.81);
+    assert_approx(torx_depth(20), 4.07);
+    assert_approx(torx_depth(25), 4.45);
+    assert_approx(torx_depth(30), 4.95);
+    assert_approx(torx_depth(40), 5.59);
+}
+test_torx_depth();
+
+
+module test_torx_tip_radius() {
+    assert_approx(torx_tip_radius(10), 0.229);
+    assert_approx(torx_tip_radius(15), 0.267);
+    assert_approx(torx_tip_radius(20), 0.305);
+    assert_approx(torx_tip_radius(25), 0.375);
+    assert_approx(torx_tip_radius(30), 0.451);
+    assert_approx(torx_tip_radius(40), 0.546);
+}
+test_torx_tip_radius();
+
+
+module test_torx_rounding_radius() {
+    assert_approx(torx_rounding_radius(10), 0.598);
+    assert_approx(torx_rounding_radius(15), 0.716);
+    assert_approx(torx_rounding_radius(20), 0.859);
+    assert_approx(torx_rounding_radius(25), 0.920);
+    assert_approx(torx_rounding_radius(30), 1.194);
+    assert_approx(torx_rounding_radius(40), 1.428);
+}
+test_torx_rounding_radius();
+
+
+
+// vim: expandtab tabstop=4 shiftwidth=4 softtabstop=4 nowrap
diff --git a/version.scad b/version.scad
index 78f2ad2..975eb67 100644
--- a/version.scad
+++ b/version.scad
@@ -8,7 +8,7 @@
 //////////////////////////////////////////////////////////////////////
 
 
-BOSL_VERSION = [2,0,427];
+BOSL_VERSION = [2,0,428];
 
 
 // Section: BOSL Library Version Functions