Tool Life Estimator

Speed up a little and tool life drops off a lot faster than you'd expect — here's roughly how much.

Reference cutting speed (SFM)

Tool life at that speed (min)

Your planned cutting speed (SFM)

Tool material

The Taylor tool life equation

V × Tⁿ = C, where V is cutting speed, T is tool life in minutes, and n is an exponent that depends on the tool material. Rearranged to compare two speeds against the same tool and material: T₂ = T₁ × (V₁ ÷ V₂)^(1÷n). Feed one known speed/life pair in, and it projects tool life at a different speed.

Why n varies by tool material

A lower n means tool life is more sensitive to speed — HSS's low n (around 0.125) is why even a modest speed increase can crater HSS tool life, while carbide's higher n (around 0.25) tolerates speed changes more gracefully, and ceramic tooling (n around 0.4) tolerates them better still. This is also the mathematical reason "just speed it up a little" hurts HSS tools far more than it hurts carbide ones.

A starting estimate, not a guarantee

Taylor's equation assumes everything else about the cut — material, feed, depth of cut, coolant, rigidity — stays constant between your reference point and your new speed. In practice, tool wear also depends on all of those, so treat this as a reasonable planning estimate to dial in from, not an exact prediction for a specific insert or edge prep.