Cutting Parameters

✅ Mild steel (S275 / EN3 / EN8 etc.)

Surface speed: 20–30 m/min
Example RPM:

  • 6mm → ~1300 rpm

  • 10mm → ~800 rpm

  • 16mm → ~500 rpm

Feed per rev (mm/rev):

  • 6mm → 0.05–0.08

  • 10mm → 0.10–0.15

  • 16mm → 0.15–0.22

✅ Aluminium

Surface speed: 60–100 m/min
Example RPM:

  • 6mm → ~4000 rpm

  • 10mm → ~2500 rpm

  • 16mm → ~1600 rpm

Feed per rev:

  • 6mm → 0.08–0.12

  • 10mm → 0.15–0.25

  • 16mm → 0.20–0.35

(Use cutting fluid / WD40 type lube to stop it grabbing)

✅ Stainless (304 / 316)

Surface speed: 10–18 m/min
Example RPM:

  • 6mm → ~600–950 rpm

  • 10mm → ~320–570 rpm

  • 16mm → ~200–360 rpm

Feed per rev:

  • 6mm → 0.04–0.07

  • 10mm → 0.08–0.12

  • 16mm → 0.12–0.18

(Key: don’t rub — keep it cutting, decent pressure, use coolant)

The simple RPM formula

If you want to calculate any size:

RPM = (Surface speed × 1000) ÷ (π × drill diameter)