feat: Thread on handle terminal piece

nhf/handle.py

@@ -164,15 +164,23 @@ class Handle:
                 height=self.rim_length,
             )
         )
-        result.faces("<Z").tag("mate")
-        result.faces(">Z").tag("base")
+        result.faces(">Z").tag("mate")
+        result.faces("<Z").tag("base")
         result = (
             result
-            .faces("<Z")
+            .faces(">Z")
             .workplane()
             .circle(self.diam_connector_external / 2)
             .extrude(self.insertion_length)
         )
+        if not self.simplify_geometry:
+            thread = self._external_thread().val()
+            result = (
+                result
+                .union(
+                    thread
+                    .moved(Cq.Vector(0, 0, self.connector_length / 2)))
+            )
         return result
 
     def connector_insertion_assembly(self):