It took a lot of work to come up with the correct thread to match the Acme thread used on broom handles.  This is a ¾" -5 Acme thread with .200 pitch and rounded thread corners to allow easy threading.  As shown in the pictures, it fits common brooms, brushes and paint roller.  The handle end fits over a 7/8" outside diameter handle and has a 1/8" hole 15 mm up from the bottom for a rivet.