TIP #4: Router bits can be specific for a material or general-purpose. General-purpose bits do not last as long or cut as well as bits specifically for the material being cut.
- Bits for cutting aluminum, such as the Belin 33-476 bits, have been designed to not melt the aluminum at the high RPMs that router cutting heads use. Generally, the maximum cut depth per pass is equal to the bit diameter. Deeper cuts can be made in multiple passes. Misters are recommended when cutting aluminum. They will prolong the life of the bit and keep aluminum from melting on the bit or the material.
- Bits for cutting plastic, such as the Onsrud 63-718 bits, have been designed to pull a large amount of material cut out of the cut path to prevent plastic melting back on the material. Deeper cuts can be done than with aluminum bits but care must be taken to prevent plastic from melting back on the material. A mister or an air hose may be used while cutting plastic to prevent melting while making deep cuts. Plastic bits are used to cut Dibond. The aluminum is thin enough that it is no problem for the plastic bits to cut. Aluminum bits will melt the plastic center back to the material.
- Bits for cutting wood have a straight cutting edge. This prevents chipping at the top edge of the material produced by spiral cut bits.
The best material cuts and longest bit life will be produced using the right bit for the right job.