One end threaded Teflon Delrin Tenon for pipe making. This is classic filtered tenon attachment for meerschaum pipes. Works great on briar pipe making too. Provides very good and durable grip if you can thread your pipe accordingly. Here is the thread tap for it: 

https://www.oxtation.com/products/thread-bit-m-8x1-25

Threaded end diameter: 5/16" - 8 mms (M8x1,25)

Straight end outer diameter: 25/64" - 10 mm

Filter in: 23/64" - 9 mms

Length: 1 37/64" - 40 mms

Warning: Although Tenon is heat-resistant, it must be kept at least 1 inch away from the fire chamber.