View Full Version : mill threading tool

02-28-2004, 12:05 PM
A good machinist friend of mine just died and left me some of his machine tooling. One item that I got is a milling threading tool.I guess I am sayilng this right. It looks like a boring bar with replacable threading inserts of different pitches that are about one inch n length. I have seen them, but don't know how to use them. Does it make the thread without the tool or the work moving?

John Stevenson
02-28-2004, 12:33 PM
These are thread mills and are used on CNC machines to produce threads, usually short internal or external threads.
They work by rotating the cutter and feeding the cutter radially into the work, usually to full depth. The work then make a interpolated move [ ie, moves in a circle ] around the cutter whilst the Z axis moves down equal to one pitch per rev.
Very fast way of producing threads as with a long cutter taking in say 10 pitches you can cut the full 10 pitches in one revolution.

They also make good internal threading bars on lathes http://bbs.homeshopmachinist.net//biggrin.gif

John S.

[This message has been edited by John Stevenson (edited 02-28-2004).]