On a lathe, the workpiece spins and the cutting tool stays still — the opposite of milling. Enter the workpiece diameter and the target cutting speed to get the spindle RPM, then use the feed rate (mm per revolution) to get the axial feed speed.
More standards, diameters and pitches in the mobile app
GET IT ONGoogle Play
Calculator
mm
m/min
mm/rev
Material cutting speed presets
| Material | HSS Vc, m/min | Carbide Vc, m/min |
|---|---|---|
| Aluminium alloys | 80–150 | 200–600 |
| Mild steel (S235/A36) | 20–35 | 80–200 |
| Alloy steel (4140) | 15–25 | 60–150 |
| Stainless steel (304) | 10–20 | 40–120 |
| Cast iron | 20–35 | 80–200 |
| Brass / Bronze | 60–120 | 150–400 |
| Titanium alloys | 10–20 | 40–80 |
Formulas
Spindle speed (RPM):
RPM = (Vc × 1000) ÷ (π × Dworkpiece)
Vc in m/min, D in mm
Axial feed rate (mm/min):
Feed = RPM × f
f = feed per revolution (mm/rev)
Example: turning a 40 mm bar at 30 m/min → RPM = (30 × 1000) ÷ (π × 40) = 239 RPM. At 0.2 mm/rev: Feed = 239 × 0.2 = 47.8 mm/min.
More standards, diameters and pitches in the mobile app
GET IT ONGoogle Play