Cutting Speed & Feed
Spindle speed, feed rate, removal rate, and pass time for milling, turning, and drilling, in mm or inch, with starting-point speeds per material.
Speed is the tool's,
rpm is the machine's.
Three equations, and why the material table is only a starting point.
The equations
Spindle speed n = 1000 × Vc ÷ (π × D) with Vc in m/min and D in mm (or n = 12 × sfm ÷ (π × D) in inches). Feed rate Vf = fz × z × n for milling (feed per tooth × teeth), or f × n for turning and drilling (feed per revolution). Removal rate Q = ap × ae × Vf for milling, ap × f × Vc for turning, and the hole area × Vf for drilling. Pass time is length ÷ Vf. If your spindle cannot reach n, the utility caps it and shows the cutting speed you actually get, because that is the number the tool life depends on.
Where the starting points come from
The material buttons fill in the midpoint of a typical range for HSS or carbide in general-purpose cutting; the range itself is shown next to the value. These are consolidated from commonly published shop tables and have not been reviewed against a specific tooling catalogue. Your tool maker's data — for the exact insert grade, coating, and operation — always wins; type it in and the calculation uses that.
What this does not cover
No chip-thinning correction for light radial engagement, no power or torque check against the machine, no tool-life model, no thread milling or tapping feeds. Diameter for turning is the workpiece diameter at the cut, so rpm changes as you face inward (constant surface speed does that for you). Inputs stay in your browser; the same four anonymous usage counts as the rest of the site apply.