Cutting Speed Calculator — Formula
## Cutting Speed to Spindle RPM
Cutting speed is the velocity at which the tool edge moves relative to the workpiece surface.
### Formula
**N = 1000 Vc / (pi D)**
where Vc is the desired cutting speed in m/min and D is the workpiece (or cutter) diameter in mm. The factor 1000 converts metres to millimetres. Recommended cutting speeds depend on the tool material and workpiece material combination.
Cutting speed is the velocity at which the tool edge moves relative to the workpiece surface.
### Formula
**N = 1000 Vc / (pi D)**
where Vc is the desired cutting speed in m/min and D is the workpiece (or cutter) diameter in mm. The factor 1000 converts metres to millimetres. Recommended cutting speeds depend on the tool material and workpiece material combination.
Exemplo Resolvido
Turning a 50 mm diameter steel bar at 100 m/min cutting speed.
- N = 1000 x 100 / (pi x 50)
- N = 100,000 / 157.08 = 637 RPM