Threading

[Oldmechthings]

Quite a number of years ago Rudy Kouhoupt published an article about a threading device for a lathe when making small threads. It is simply a knurled cylinder with a pilot hole through the center, and a 1" diameter pocket in one end and 13/16" diameter in the other to hold dies. A pilot bar or guide is mounted in the tail stock chuck to hold it in line. I use mine a "lot". It works good up to about 1/4", but beyond that it is difficult for me to grip it tight enough. You hold it with your bare hand, and push it against the rotating workpiece, and it starts cutting the threads. When it is threaded to the length, just release the grip, and the cylinder starts to spin with the workpiece. Stop the lathe, reverse it, grip it again, and back it off. Frequently I want to thread right up to a shoulder, so I let it go until the die hits the shoulder. Then I back it off, take the die out and turn it over so the untapered threads are leading, then run it up against the shoulder again, and it finishes cutting that last thread or two right to the shoulder. I do not know if dies are supposed to be used that way, but I've been doing it for years without a problem. Oh, I forgot to mention that I thread at whatever speed the lathe was set at to turn the part. Usually 500 to 800 RPM. And I also add a drop or two of threading lubricant before starting the threads.