202 Agricultural Mechanics and Technology Systems
Copyright Goodheart-Willcox Co., Inc.
Band Saw Blades
Band saw blades vary in composition, length,
thickness, width, tooth style, and teeth per inch
(TPI). It is important not only to select a blade
that will fi t a particular saw but to also select the
blade with the proper characteristics for cutting the
selected material.
The regular tooth confi guration, which is
useful for thin cuts in most materials, has each
tooth beginning at the base of the last and a very
slight 0° to 1° positive or forward rake angle.
The rake angle is the number of degrees off
perpendicular to the back of the blade each tooth
is angled. For wood, plastics, and soft metals, a
skip tooth confi guration may work better because
the extended gullet allows more room for chips
to clear from the kerf. A hook tooth confi guration
may be used with thicker wood, plastics, and some
metals because it uses an aggressive 10° positive
rake angle to make faster cuts. Figure 8-32A shows
the three blade confi gurations and blade terms.
The number of teeth per inch (TPI) on a blade
not only helps to determine the size and type of
material a band saw cuts, it also infl uences the
speed at which the blade operates and the feed
rate, or how fast the blade cuts. Common TPI
counts for band saws range from 2 to 32 TPI.
Blades with coarse teeth (2 to 6 TPI) are suited for
cutting thick wood, and blades with fi ne teeth (18
to 32 TPI) should be selected for cutting thinner
materials, plastics, and metals. The coarser the
teeth, the faster a blade can cut. Finer teeth require
a reduced feed rate and produce a smoother fi nish
than a blade with a low TPI.
When deciding how many teeth per inch are
required for a given job, the accepted rule is that
at least three teeth must be engaged in the work
while the band saw is cutting. This practice is done
for maximum effi ciency and to prevent damage
to the blade. In general, harder materials require
a higher TPI to distribute the cutting pressure to
a greater number of teeth in order to reduce
blade wear.
There are generally three types of blade set
found on band saw blades: alternate set, raker set,
and wavy set. See Figure 8-32B. On blades with
alternate set, each successive tooth is alternately
B
Amy Walters/Shutterstock.com
Figure 8-31. Vertical band saws are found in many
different applications. Different blade styles and
speeds are used based on the material being cut.
A—Study the parts of a band saw. B—A close-up
of the band saw blade and upper blade guide assemly.
Removable
table insert
Upper blade
guide assembly
Blade
Power
switch
Belt tension adjustment
Wheel (upper)
Height
adjustment
Depth
of cut
Throat
capacity
Table
Wheel (lower)
A
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