For those interested, I run stainless at 200fpm roughing, 350fpm finishing. Depending on the steel being turned, I run 12L14 at [email protected] for roughing, and 1100fpm [email protected] DOC. 8620 will run a little less, but not much, with the DOC remaining the same. These are using flood coolant.
The Seco/Carboloy recommended feeds and speeds are higher than that but the tool life is greatly less. I use TIcn coated inserts but find the TINal inserts last longer. I can run 4 hours (half a day) on one corner, index the insert after lunch, and run the rest of the day.
Another thing interesting is that the insert manufacturers are placing the various materials in catagories based on the materials machinability and placing this information on the label of the insert container.
The formula I use for SFPM is simple, Pi * DIA/12 * RPM. (Pi =3.1416)
Steve