βš™οΈ Machining

Cutting Speed / RPM Calculator

Spindle speed (RPM) & table feed rate β€” metric or imperial

πŸ”§ Cutting Parameters
πŸ”„ SPINDLE SPEED (N)
-- RPM
N = (Vc Γ— 1000) / (Ο€ Γ— D) [metric] | N = (Vc Γ— 12) / (Ο€ Γ— D) [imperial]
πŸ“ˆ TABLE FEED (Vf)
-- mm/min or IPM
Vf = N Γ— fz Γ— Z
πŸ“– How to Use This Calculator

Enter the cutting speed (Vc) recommended by your tool manufacturer β€” typically found in the tool catalog for the specific work material. For HSS tools on mild steel, a common starting point is 25–35 m/min. For carbide inserts, 150–300 m/min depending on coating and material.

Enter the tool diameter (D) in mm (metric) or inches (imperial). The calculator uses the formula N = (Vc Γ— 1000) / (Ο€ Γ— D) to give you spindle RPM.

For milling cutters, enter feed per tooth (fz) and number of flutes to get the table feed rate (Vf = N Γ— fz Γ— Z). This is the value you enter in the CNC program as F-word.

Typical Cutting Speeds (Starting Point)

MaterialHSS (m/min)Carbide (m/min)
Mild Steel25–35150–250
Stainless Steel10–2080–150
Aluminium60–100300–600
Cast Iron20–30100–200
Brass / Bronze60–90200–400

Note: These are starting values. Always refer to the tool manufacturer's recommendations and adjust based on machine condition, coolant availability, and actual surface finish requirement.