Need Help!- Turning 40-45 rockwell

[bugzpulverizer]

I need to face off about 1 1/8" of length from a 2.75 diameter bar that is 40-45 rockwell. Is that doable? What recomendations does anyone have on doing this? (i.e. SFM, insert, DOC) Any help would be appreciated. Thanx!

[philserveng]

talk to your tooling rep about ceramic tips, they are expensive but they are designed for hard metal turning.....and they work.

[DareBee]

Any decent coated carbide will cut that.
We do it all the time with DNMG-432-GM (TG-320 coating)
My guys have been doing most if this stuff but I am thinking 100ish SFM, .010-.012/rev .03DOC.
The hard part is the center tit. Will almost always chip the insert (if you are at the 50+Rc end).
I like to do a centerdrill or something (I don't know your part or application?).
Milling that is NO problem either and sometimes easier.

[bugzpulverizer]

Thanks for the info! That helps.

[g-codeguy]

Why don't you use a cut-off tool and leave enough material to make a finishing pass with a standard 80 degree tool?

[pareicher]

We do it day in and out. A good standard insert will work fine. We use KC935 at around 250SFM. Should be no problem. take about .04" to .05" per pass.