Cutting Speed and RPM on the Lathe and Mill

[Mayhem]

I'd just convert the metric to inch to make it easier, otherwise you would need to know the surface meters per minute for each material. So if you are running a 10mm endmill in 1018 the calculation would be:

4 x 100
0.394 (10mm) = 1015 rpm

note: 1mm = .0394"