Ted Edwards wrote in message ...

"You need to turn at really high speed to use carbide." You *may* run
carbide at much higher speed than HSS but you don't *have* to. I run it
at whatever speed I feel comfortable and my machine can handle.
There's more but I suggest you try it for yourself.

Ummm, Ted. The only thing we used that tiny an insert on was one of
the shaft gears we used to make. 3" diameter, 670rpm, .022 feed, and
3/16" per side. I don't think any chinese 3n1 is going to come
anywhere near reaching what the insert is capable of. Oh yeah. 8620
normalized forging. Industry didn't design carbide for slow light
cuts. It's meant to rip metal off as fast as possible. Home shop
machines don't have the backbone to handle what the carbide was
intended for.