How to Properly Install a Router Bit

Modern plunge router
By AussieLegend (Own work) [Public domain], via Wikimedia Commons

A power router is a remarkable simple tool in design. The cutting bits are attached to the end of the motor spindle, and as the motor spins, so does the cutting bit, at speeds that reach as high as 25,000 or 30,000 rpm. But this high speed comes with risks. To use router bits safely and to get the best results, the router bits need to be installed properly into the router's collet--the piece that grips the cutting bit and keeps it attached to the motor spindle.

Improper installation of a router bit can cause excessive oscillation (chatter) and can increase the likelihood that the bits will break when in use.

Before beginning any routing operation, check your bit to make sure that it is clean, relatively free of pitch, and most of all, sharp. If the bit is dull, chipped, excessively burned or has any other defect, it should be sharpened or replaced before use.

When installing the bit into the collet, the bit should not be completely inserted to the face of the collet for routing. Instead, insert the bit until the shank reaches the bottom of the collet, then ease it back out about 1/8 -1/4" before tightening the collet. When the bit is tightened, there should be a minimum of  3/4" of the shank gripped in the collet. If your bit's shank is too short to ensure a 3/4" grip, then the bit should be replaced.

Other safety features to keep in mind:

  • Second, be sure to set your router to the proper speed for your router bit. Setting your router to an incorrect speed will not only affect the router's performance but also can cause the bit to break much more easily.
  • Also, before beginning any routing operation, be certain that you give the router's motor time to come up to full speed for the chosen setting. Beginning to route before the bit is at full speed can give poor results.