[smokediver576]

Okay, Slant Pro and other lathe users. I need to turn some 304 and 316 stainless steel and need some help. I must be doing something wrong because I keep toasting inserts. I’m turning some cones out of 1” and 1.25” rod stock. The cones are approximately .875” tall. I am using the standard Tormach steel inserts. Please post up your feeds and speeds recipes. I’ve watched the videos on Tormach’s site but they do not address max RPM or depth of cut.

Thanks!

[coffeetek]

I use 303 and WNMG inserts. Use constant surface speed: 203 ft/min (62m/min). Feed per revolution 0.01" (0.254mm), roughing step down to 0.0315" (0.8mm) I set maximum spindle speed to 1500.

Breaking very nice C and 6 chips, lot of coolant, inserts lasts forever. I would start with these parameters.

[smokediver576]

I use 303 and WNMG inserts. Use constant surface speed: 203 ft/min (62m/min). Feed per revolution 0.01" (0.254mm), roughing step down to 0.0315" (0.8mm) I set maximum spindle speed to 1500.

Breaking very nice C and 6 chips, lot of coolant, inserts lasts forever. I would start with these parameters.

Thanks for the info.

I ended up going with 700 SFM (although I had max RPM set to 1500....) .004 IPR, .05" DOC and had really good results. I had to switch from the 3/8" Rapid Turn tools to the 3/4" tools. Kept smoking the smaller inserts. I need to invest in some stainless steel specific inserts.

[Tarzan63]

I machine quite a bit of stainless. If you are running 700 SFM you will be burning up inserts. I run about 325 SFM with 304 and a feed of .01 to .012 IPR. You need a slower speed and a harder feed. You want to break a chip and let the chip carry away the heat. Then up the SFM to 450 to 500 SFM to finish and .003 IPR .