Check the feed rate table on your lathe. You have a feed rate which is equal to 30tpi. Also calculate the available metric pitches to see if one is close enough to work. In both cases you will have to leave the lathe engaged and reverse to go back to the start. I have used the feed to cut odd threads sucessfully a number of times. Regards, Bill.

I purchased a new barrel for a Win 97 shotgun.When attempting to install it discovered that the threads were either not cut deep enough (minor diameter) or not cut on the right side of the threads on the last pass or two.Even though the major diameter and thread pitch is correct the collar and threaded sleeve wil not turn on to the new barrel.Went to correct this and found my lathe quickchange gearbox does not have 30 T.P.I.-jumps from 28 to 32.Cannot use a wrench to force the collar on as it is so thin in spots it would fold from the pressure and new ones are not available.Any siggestions appreciated.Frank.

Hi Bill,
My South Bend Heavy 10 has the 480tpi gearbox on it and has 30tpi. The feedrate is .0112. My SB 9" has the 224tpi gearbox and jumps from 28-32tpi. If I ever have to turn the 480tpi I will let you grind the bit for me.

Centurion
If you need my help please send me the pieces and I can recut that thread for you. Jerry