diff --git a/THREAD_TABLE.scad b/threadlib/THREAD_TABLE.scad
similarity index 100%
rename from THREAD_TABLE.scad
rename to threadlib/THREAD_TABLE.scad
diff --git a/BSPthread/autogenerate.awk b/threadlib/autogenerate.awk
similarity index 100%
rename from BSPthread/autogenerate.awk
rename to threadlib/autogenerate.awk
diff --git a/BSPthread/BSPthread.jpg b/threadlib/img/BSPthread.jpg
similarity index 100%
rename from BSPthread/BSPthread.jpg
rename to threadlib/img/BSPthread.jpg
diff --git a/threadlib/test.scad b/threadlib/test.scad
new file mode 100644
index 0000000..bbd41a5
--- /dev/null
+++ b/threadlib/test.scad
@@ -0,0 +1,45 @@
+/* Test and demonstrate thread library */
+
+use <threadlib.scad>
+
+module bolt(designator, turns, fn=120) {
+    union() {
+        specs = thread_specs(str(designator, "-ext"));
+        P = specs[0]; Dsupport = specs[2];
+        H = (turns + 1) * P;
+        thread(str(designator, "-ext"), turns=turns, higbee_arc=20, fn=fn);
+        translate([0, 0, -P / 2])
+            cylinder(h=H, d=Dsupport, $fn=fn);
+    };
+};
+
+module nut(designator, turns, fn=120) {
+    union() {
+        specs = thread_specs(str(designator, "-int"));
+        P = specs[0]; Dsupport = specs[2];
+        H = (turns + 1) * P;        
+        rotate(180)
+            thread(str(designator, "-int"), turns=turns, higbee_arc=20, fn=fn);
+
+        translate([0, 0, -P / 2])
+            difference() {
+                cylinder(h=H, d=Dsupport * 1.1, $fn=fn);
+                translate([0, 0, -0.1])
+                    cylinder(h=H+0.2, d=Dsupport, $fn=fn);
+            };
+    };
+};
+
+
+type = "G1";
+turns = 5;
+
+intersection() {
+    color("Green")
+        translate([-100, 0, -100])
+            cube(200, 200, 200);
+    union() {
+        bolt(type, turns);
+        nut(type, turns);
+    };
+};
diff --git a/BSPthread.scad b/threadlib/threadlib.scad
similarity index 64%
rename from BSPthread.scad
rename to threadlib/threadlib.scad
index cdb0ed7..050eef2 100644
--- a/BSPthread.scad
+++ b/threadlib/threadlib.scad
@@ -41,7 +41,6 @@ module thread(designator, turns, higbee_arc=45, fn=120)
 {
     specs = thread_specs(designator);
     P = specs[0]; Rrotation = specs[1]; section_profile = specs[3];
-    echo(designator, "Rrotation", Rrotation);
     straight_thread(
         section_profile=section_profile,
         higbee_arc=higbee_arc,
@@ -49,28 +48,3 @@ module thread(designator, turns, higbee_arc=45, fn=120)
         turns=turns,
         pitch=P);
 }
-
-
-// testing:
-
-type = "G1";
-intersection() {
-    color("Green")
-        translate([-100, 0, -100])
-            cube(200, 200, 200);
-                union() {
-                    echo("Dsupport", thread_specs(str(type, "-ext"))[2]);
-                    thread(str(type, "-ext"), turns=3, higbee_arc=20, fn=120);
-                    translate([0, 0, -1.2])
-                        cylinder(h=9, d=thread_specs(str(type, "-ext"))[2], $fn=120);
-
-                    rotate(180)
-                        thread(str(type, "-int"), turns=3, higbee_arc=20, fn=120);
-                    translate([0, 0, -0.9])
-                        difference() {
-                            cylinder(h=9, r=200, $fn=120);
-                            translate([0, 0, -0.1])
-                                cylinder(h=10, d=thread_specs(str(type, "-int"))[2], $fn=120);
-                        };
-                };
-};
diff --git a/BSPthread/BSPthread.xlsx b/threadlib/threads.xlsx
similarity index 100%
rename from BSPthread/BSPthread.xlsx
rename to threadlib/threads.xlsx