We recently wrapped up a turning job for a local pump manufacturer — 200 pieces of 316 stainless steel shafts, each 18 inches long with a 1.25″ diameter and several turned-down journal diameters along the length. Tolerances on the journals were ±0.0005″, which is where things get interesting with stainless.
We ran these on our Mazak QuickTurn 200, using Sandvik inserts specifically rated for stainless. Cutting speed was kept conservative at around 300 SFM to avoid work hardening — a big issue with 316 if you’re not careful. Coolant pressure was cranked up to keep chips clearing and prevent re-cutting.
The main headache was chatter on the longer unsupported sections. We ended up using a steady rest on anything over 10 inches from the chuck. Once we had the setup locked in, the parts came out clean and within spec. This is bread-and-butter work for us — stainless turning is something we do every week.