Today my pop set me up on making the brass air vent stem part. It's basically a screw with a slot running up the threads with an O-ring at its base so that when it is loosened on the surfboard or paddleboard it will release the air pressure inside of the board.
Starting with 1/2 inch (500/1000's) stock brass we cut the pieces at 7/8's of an inch as the final product will be 3/4". This give some margin for error and chucking the pieces in the lathe easier. The part is then put on the lathe set on high speed and the threaded part needs to be 3/8" (375/1000's) wide and 1/2" long. So that is cut on the piece before it is threaded.
Then the part is threaded with the lathe set on slow speed and shut off so it stops spinning just as the threading die reaches the head of screw.
And there you have it!
A bunch of these were made by me today. Fun stuff with dad!