198 Agricultural Mechanics and Technology Systems
Copyright Goodheart-Willcox Co., Inc.
Saws cut by chiseling away tiny bits of material
in the path of the blade. It is important to understand
that these tiny bits add up to waste material. The
path cut away by a saw is called the kerf, shown in
Figure 8-25. The width of the kerf is the same as the
width of the widest part of the blade. The teeth of a saw
are alternately turned slightly to right and left of center
to create blade set. Blade set ensures that the teeth
remove enough material so that the body of the blade
has clearance as it passes through the kerf. Too little
clearance for the blade allows friction to build up heat
in the blade. Hollow ground blades, or thin kerf
blades, do not use blade set to create clearance.
Instead, the tips of the teeth are thicker than the
body of the blade, resulting in the removal of less
material and reduced waste.
Most circular saw blades are made from steel. High-speed steel is used
in higher quality blades to increase durability and maintain blade sharpness
longer. Blade teeth can be tipped with sharp inserts made from tungsten
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Figure 8-25. The set of the teeth on a saw blade
creates a kerf that is wider than the thickness
of the blade in order to provide clearance. This
reduces friction and allows waste material to be
removed as the cutting action progresses.
STEM STEM Connection Connection
Saw Blade Designs
Use a caliper to record an outside measurement of the thickness of a saw blade, Figure A, and an
inside measurement of the kerf it produces, Figure B. Subtract the width of the kerf from the thickness of
the blade. The difference is the clearance. Take these measurements on a crosscutting blade, a ripping
blade, and a combination blade. If other types of saws are available, measure them as well. Determine
whether the clearance is different for different types of saw blades.
Figure A
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Figure B
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