Some General Tooling Recommendations

• Use single edge router bits when speed is the primary consideration and finish is less important. 
• Use double edge router bits when finish is the primary consideration. 
• Use upcut spiral router bits for grooving, slotting or when fast chip removal is required. 
• Use spiral, straight or shear tools for natural woods depending on type of cut required. 
• Use spiral, straight or shear carbide tools for composites, particleboard, plywood or MDF. 
• Use spiral tools when finish and/or available horsepower are problems. 
• The cutting length of the tool is very important to the finish. 
• Use the shortest cutting length allowable, based on the material thickness. Using a tool with a cutting length that is longer than required can cause vibration, deflection and an inferior finish.
• In general, the cutting length should not be more than four times the cutting diameter. Bits with a cutting length over four times their diameter will be subject to increased breakage. 
• Use the largest tool diameter allowable for increased rigidity, finish and tool life.

Solid Tungsten Carbide Router Bits

Tungsten carbide cutters are made up of very hard particles of tungsten carbide bound together with metallic cobalt. Bits produced with this material are very strong and durable and tend to stay sharper longer than High Speed Steel (HSS) tools. This type of cutter likes to be worked hard with high feed rates. because they are hard they can be brittle and do not like shock loading. Do not drop these cutters or subject them to sudden impact.

Carbide-Tipped Router Bits

Carbide-tipped tooling provides some of the edge longevity of carbide with the lower cost of a steel base. Carbide tipped bits are only available with straight flutes

High Speed Steel (HSS) Router Bits

HSS is a poured material, chemically and metallurgically bonded together. The steel is processed from raw ore and heated to a liquid stage where several minerals and elements are added to improve the internal structure. Typically, HSS tool life is not as long as carbide, however they can withstand shock loading better than carbide cutters.

Ceramic and Diamond Coated Router Bits

This tooling is worth considering when carbide’s life is not acceptable. The major consideration with these tools is the cost of the coating materials and generally reduced feed rates.