Tapping RPM calculator
Taps break — usually because they run too fast. Pick the material and tap diameter for a safe starting speed, with a bonus for coated taps.
Why tapping runs much slower than drilling
A tap cuts a full thread profile with its whole circumference engaged, can't evacuate chips easily, and — unlike a drill — cannot simply be pulled out under load. That's why tapping speeds are a fraction of drilling speeds in the same material: the formula is the same (n = (Vc × 1000) / (π × Ø)), but the safe Vc is far lower.
What does the coated-tap option do?
Coatings like TiN or TiCN reduce friction and heat, allowing roughly +5 m/min on the cutting speed — the same rule the original desktop version of this calculator uses.
Machine tapping vs. tapping by hand?
These speeds are for machine tapping (drill press with tapping head, mill, or CNC rigid tapping). By hand, speed is irrelevant — but the same rule applies: cutting fluid, steady pressure, and break the chip by backing off regularly in tough materials.
Are these values safe to use directly?
They are conservative starting values for HSS taps with cutting fluid. Blind holes, deep threads and gummy materials warrant going slower. Always respect your machine's limits and the tap manufacturer's data.
Is my data sent anywhere?
No — this runs entirely in your browser with plain JavaScript. Nothing is uploaded.
