Threading with triangular inserts

Tip radius for TPG322 is 1/32", for TPG321 it's 1/64". According to my homemade hand grinding chart 0.016" is about right for 8 - 12TPI. You could try it on finer threads and drill out the female thread a little if it doesn't fit well.

jw

download and install the thread calculator on this page Ig.

A Zero TNR is about .003"-.005". A one is .015". You can purchase threading inserts if you need to hole print tolerances but what you need to worry most about is the pitch diameter and form.

JC

Carbide likes higher speeds and deeper DOC. This makes using it for manual threading difficult at best. You'd do best to stay with HSS.

Now for my CHNC lathe, I use carbide threading inserts and thread around 2000 RPM. Works great. But these aren't TPG, they are just for threading.

Karl

Yep. Check this link:

I've used the smaller radius inserts for threading. They also have dedicated threading tools which look nice, pricey though. Their inserts are T-15 HSS, and pretty sharp. They're nice folks to call and talk to.

Pete Keillor

Pete sez: Yep. Check this link:

Nice site Pete. Thanx. Inserts are great for threading but don't forget the absolute minimum-radiused nose for fine threading can be achieved with HSS.

Bob Swinney

These are HSS inserts. You can grind them as well, say for lead angle, although I haven't tried that. Dick Triemstra got me onto these when he sold me the lathe in 2001. They're better than carbide in most instances for the low power, less rigid machines we hobbyists have. Yeah, I do grind HSS for some stuff, internal threading, shaper bits, etc.

Pete Keillor

My lathe is 3 HP, 1,400 lbs. So it is heavy enough for carbide.I have looked a lot at carbide threading tools, on ebay, and I have not found anything worth buying. I will stick to HSS tools for now.

i