Single Point Lathe Threading - Best Technique Ever

[Crusty]

I tried the method suggested by Joe Pieczynski in this video and the 25W light bulb above my hat came on. The tool is mounted on center upside down and the lathe is run in reverse so that the cut proceeds from left to right starting at the shoulder, and it makes tool crashes a thing of the past because the cut finishes out in clear air.

Here's a pipe that I threaded today with Extra Fine threads and it was low stress easy, the threads are perfect and I'm happy with this outcome.



You do have to grind a tool to cut the threads because all the pre-ground ones have the fat side on the right, which becomes the left when it's turned upside down, and that will prevent you from getting the bit into the gutter to start in many cases. It's simple though, just grind a bit as a mirror image of a normal threading bit with the fat side on the left instead of the right. Don't forget to turn your compound 29½º the other way.

Another useful demystifyer from Joe: If the chuck and the lead screw rotate the same direction then it will be a right hand thread - if they rotate opposite directions it will be a left hand thread.

I'm pleased that I learned how to do this.

[DIYer]

Thanks Crusty! We've added your Single Point Lathe Threading Method to our Tapping and Threading category,
as well as to your builder page: Crusty's Homemade Tools. Your receipt:

Single Point Lathe Threading Method by Crusty

tags: threading

[Tonyg]

For machining techniques Joe Pieczynski is worth following, he has some novel ways of doing some things and his explanations are superb.

[Crusty]

I agree. His company, Advanced Innovation Concepts, is aptly named.

[bruce.desertrat]

I just wish he'd invest in a tripod...I'm one of those unlucky folks who will get really nauseous watching that horribly shaky video. You're explanation, though, Crusty, sounds simple enough for a dumdum like me to follow, though!

[Crusty]

I totally agree about the videography. Someone who's even worse is Abom79 who feels the need to follow the motion of his shaper head with the camera and often I get queasy watching his vids.

[Hans Pearson]

Thanks Joe, thread cutting has always been a frightening experience for me. I am definitely going to try this next time though.

[Crusty]

Here's how I use this technique and it's quick too. I set a carriage stop on my ways at the beginning point of the thread (in the gutter) and the carriage against the stop, then rotate the chuck by hand until a number lines up on the dial and engage the threading lever. At the end of a cut after disengaging the threading lever I back my cross feed out exactly 1 turn, return the carriage until against the stop, rotate the chuck by hand until that same number comes up on the dial and engage the threading lever, run the crossfeed back in exactly 1 turn (helps to set a zero on the dial), increase my depth of cut with the compound and start the lathe for the next cut. Easy peasy and no destroyed tools or anxiety over hitting the number.