General Guidelines for
Tooling and Materials
Technoisel
TOOL MATERIALS
Solid Carbide
Use for all natural woods, wood composites and hard, fibrous or abrasive plastics.
Solid carbide is generally the toughest tool (next to diamond tooling) and holds the
edge best.
Carbide Tipped
Use for plywood and coarse wood composites. Carbide tipped tooling provides
some of the edge longevity of carbide with the lower cost of a steel base.
High-Speed Steel
Use for aluminum, soft natural woods and ABS or poly plastics. High-speed steel
is the most readily available tooling and is preferred for most metal work because
of its cost and hardness. HSS is seldom used in wood applications because carbide
tooling stays sharper longer. HSS is generally preferred for metal cutting and
some plastic cutting operations.
TOOL GEOMETRY
Straight Flute
Use for wood and plastic hand-feed operations. The straight flute design, in single
or multiple cutting edge, produces a clean finish. The harder the material, the
more cutting edges are recommended.
Spiral Flute
Use for aluminum, wood and plastic machine-feed operations. The spiral flute is
especially good at cleaning chips. When cutting aluminum and plastic, remelting
of the chips is primarily the source of poor cut quality.
Chipbreaker
Use for wood roughing or hogging machine-feed operations. The chipbreaker
edges increase the overall cutting edge length allowing for much faster feed rates.
FLUTE GEOMETRY
Single Flute
Use for faster feed rates in softer materials. The single-flute cutter typically has
lots of room for chips, but the single cutting edge limits either the feed rate or the
hardness of the material to be cut. These types of cutters are especially
recommmended for plastics.
Double Flute
Use for better finish in harder materials. Double-flute bits provide a smoother
cutting action because the chip load is smaller than a single-flute cutter for a given
feed. This allows harder materials to be handled.
Upcut Spiral
Use for grooving or slotting, for upward chip evacuation and best finish on bottom
side of piece part. These bits allow for rapid cuts since the tool clears the chips
away from the material. This type of tool is not recommended for softer materials
such as MDF because of the ragged finish that can result on the top surface.
Downcut Spiral ¯
Use for downward chip flow, better holddown in fixture and best finish on top side
of piece part. Note that the cutting speeds usually have to be reduced because
the chips are pushed back into the material.
Up/Down Spiral
Use for double-laminated material and best finish on top and bottom side of piece
part. Because of the spirals, all the chips are forced back into the material. This
results in a very clean cut on the top and bottom edges, but the cutting speeds
have to be reduced. Note that the center of the spirals should be approximately in
the center of the material for best results. This usually means that a substantial
scavenger board would have to be used.
NOTE: This router bit selection guide indicates the most popular tool series used for cutting the material indicated.
Your specific requirements may vary, so be certain to examine other alternatives in the section to which you
are directed by the selection guide.
