Sharpening Router Bits

Just like any other cutting tool router bits can be expected to dull or damage overtime. Carefully inspect your bits after each use. If there is damage that can’t be corrected with a simple touch up, consider sending the bit to a professional or, if the router bit is not extremely expensive, you may decide to discard and replace the bit. You alone are responsible for your safety and quality of craftsmanship. Having that said, there are a few things you can do to improve to cut and prolong the life of your router bits.

First, clean router bits regularly. Buildup of pitch and tar, known in some circles as crud, in many cases can be easily removed.

1) If the bit has a bearing remove it if possible.

2) Try to first remove the pitch by soaking it in good quality de-greaser style dish soap. Scrub with an old toothbrush. You may be surprised how just a few minutes of soaking and a little scrubbing will clean the bit. If that is not successful try cleaning with a little lacquer thinner or oven cleaner. This is only as a last resort. Soaking in the de-greasing dish soap can be increased to a few hours, but not overnight. Should there still be some residue left try scraping the blade with a rigid piece of plastic. Again, you will be amazed at the results. Be sure the bit is free of chemicals and completely dry after cleaning.

3) Sharpen with a fine (600 grit) diamond file or credit card size diamond card. It is better to use fewer strokes, four or five, and a couple drops of stone sharpening oil. Be sure to use an equal number of strokes on each blade. Sharpen only the flat side of the cutter. Keep the blade flat and only use a moderate amount of pressure.

4) Repeat the above process using the extra fine (1200 grit).

A few closing suggestions. This technique will work on high speed steel or carbide cutters. You will be best served, if your budget allows, only buying carbide cutters as they will last longer and hold an edge much better. This is an example of the old adage, “pay me now or pay me later”. Don’t attempt to sharpen spiral router bits. That job is best left to the professionals.