Estimates the spindle power and torque required for a milling or turning cut, based on material removal rate and the specific cutting force of the material. Useful for checking whether a machine has enough horsepower for a heavy roughing pass before you run it.
Cutting Parameters
Material
Results
This is cutting power only (the energy actually removing material) divided by your machine efficiency estimate to approximate the power draw at the spindle motor. Add margin beyond this number — running a machine at its calculated limit leaves no room for tool wear, work hardening, or interrupted cuts.
How It Works
Material removal rate is depth of cut × width of cut × feed rate, converted to cm³/min. Cutting power follows the standard specific-cutting-force relationship: power (kW) = MRR (cm³/min) × kc (N/mm²) ÷ 60,000, then divided by your machine efficiency to estimate the power actually drawn at the motor (accounting for spindle bearing friction, belt/gear losses, etc.). Torque is back-calculated from power and RPM using torque (N·m) = 9550 × power (kW) ÷ RPM.
FAQ
Where do the kc values come from? They are typical specific cutting force values for general-purpose machining at moderate feed rates — actual kc varies with alloy, hardness, and chip thickness, so treat the material presets as a reasonable estimate, not a guaranteed number. For a known material and tooling combination, use the Custom option with a value from your tooling manufacturer’s data if available.
Why is my calculated power higher than the cut actually feels? Specific cutting force assumes continuous full-width engagement. Climb milling, trochoidal paths, or light radial engagement reduce average load well below this worst-case estimate.