MetalworkingFun Forum

I'm threading a part for my mill. My full forming carbide inserts for my lathe are labeled 24 UNJ ( 16 ER 24 UNJ) all my other inserts are just UN. Like 20 UN (16 ER 20UN). What's the difference between UN and UNJ threads?

More than you might want to know about it ...

http://www.threadcheck.com/whats-the-j-i...nicalinfo/

... or maybe nothing that you really wanted to know ...

Just right. Good to know, how and why. but different they are.