Safe Speeds for Big Router Bits
A slower speed can make routing safer and improve the quality of the cut
The speed at which a router bit turns can be important. The typical router runs at about 22,000 rpm, which is fine for most bits. But as the diameter of the bit increases, you’ll want to slow things down. In the worst-case scenario,
a big bit at full speed could spin itself apart. Before that happened, the bit would begin to flutter, which would cause even a brand-new bit to leave burnt edges or a rippled finish.
When using big bits, decreasing router speed can make routing safer and improve the quality of the cut. Don’t think big bits can remove all that wood at once. To prevent damage to the bit or board, take light cuts and slow down the router to a safer, slower speed.
Below is a chart showing recommended speeds for various sizes of bits. If you find yourself burning edges with fresh bits, you may choose to use a speed slower than what’s listed below. To be extra safe, big bits should be used only in a router table.
|Bit diameter||Recommended rpm|
|1 in. or less||Full speed|
|1 in. to 1-1/2 in.||18,000|
|1-1/2 in. to 2-1/2 in.||15,000|
|More than 2-1/2 in.||10,000|
Excerpted from Furniture You Can Build, p. 140