Find the correct RPM range for your bit diameter to get clean cuts and prevent burning.
For dense hardwoods (maple, hickory) use the lower end of the range to reduce heat. For softwoods and MDF, the middle of the range works well. Always start at a lower speed and increase if chatter occurs.
Full reference
| Bit diameter | Min RPM | Max RPM | Max tip speed (fpm) |
|---|---|---|---|
| Up to 1" | 22,000 | 24,000 | 6,283 |
| 1" – 1-1/2" | 20,000 | 22,000 | 8,639 |
| 1-1/2" – 2" | 16,000 | 18,000 | 9,425 |
| 2" – 2-1/2" | 12,000 | 16,000 | 10,472 |
| 2-1/2" – 3" | 10,000 | 12,000 | 9,425 |
| 3" – 3-1/2" | 8,000 | 10,000 | 9,163 |
| Over 3-1/2" | 6,000 | 8,000 | 8,378 |
Router bit speed is limited by tip (peripheral) speed — the velocity at which the cutting edge moves through the wood. Too fast and the bit burns the wood and dulls quickly; too slow and the cut is rough and chattery.
A 3″ bit spinning at 24,000 RPM has a tip speed of roughly 18,850 feet per minute — dangerously fast and likely to cause vibration or even bit failure. The same router dialled down to 10,000 RPM gives a safe 7,854 fpm.