Barrie I find the easiet way to screw-cut is to stop the lathe at the end of the cut, withdraw the tool, and reverse the lathe - in this way whatever the thread, it is always on track. I bought an ancient Hardinge last year, and with this lathe, screwcutting at speed is a doddle! You can thread up to a shoulder, and the lathe will stop. The topslide has a device for withdrawing, and the reverse on the screwcutting does not lose the track Hardinge suggest that you do not screwcut above 1000 rpm! Cheers! Hubert ----- Original Message ----- From: "Barrie Purslow" <bpduo@xxxxxxxxxxxxx> To: <modeleng@xxxxxxxxxxxxx> Sent: Monday, August 14, 2006 11:57 AM Subject: [modeleng] Re: Mystery Thread & New Loco > Al, > > The thread had stripped about 1/2" into the end of the tube but the original > thread was about 3/4" long so I set up the thread cutting operation to > extend the remaining thread using a tpi of 26. I suspect the thread is > actually 1mm pitch as the new thread does go slightly tight when a collet is > screwed in more than 1/2". I avoided the metric pitch because, although my > lathe will cut them, it is not possible to release the clasp nut from the > leadscrew between passes! I felt sure this would result in a catastrophe! > > Regards, > > > Barrie > > > MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.