Filter
Top Products
27
Blade Selection
Using the proper blade for the job will increase
the operating efficiency of your band saw, help
reduce necessary saw maintenance, and
improve your productivity. Thus, it is important to
follow certain guidelines when selecting a saw
blade.
Here are factors to consider when selecting a
blade:
• The type of material you will be cutting.
• The thickness of the workpiece.
• The features of the workpiece, such as
bends or curves with small radii.
These factors are important because they
involve basic concepts of saw blade design.
There are five (5) blade features that are
normally changed to meet certain kinds of
sawing requirements. They are:
1. width
2. pitch (number of teeth per inch)
3. tooth form (or shape)
4. the “set” of the teeth
5. the blade material itself
Width
Band saw blades come in different standard
widths, measured from the back edge of the
blade to the tip of the tooth. Generally, wider
blades are used for ripping or making straight
cuts, such as resawing. Narrower blades are
often used when the part being cut has curves
with small radii. When cutting straight lines with
a narrow blade, the blade may have a tendency
to drift (see “Blade Lead”).
Pitch
Pitch is measured in “teeth per inch” (T.P.I.) and
can be constant or variable. Figure 55 shows
blades with different pitches.
Figure 55
A fine pitch (more teeth per inch) will cut slowly
but more smoothly. A coarse pitch (fewer teeth
per inch) will cut faster but more roughly.
As a rule of thumb, the thicker the workpiece,
the coarser will be the blade pitch. If you have to
cut a hard or very brittle material, you will
probably want to use a blade with a finer pitch in
order to get clean cuts.
Using a blade with too few teeth may cause
vibration and a rough cut, while too many teeth
may cause the gullets to fill with sawdust and
overheat the blade.
As a general rule, try to use a blade that will
have from 6 to 12 teeth in the workpiece at any
given time.
Shape
Figure 56 shows common types of tooth shape,
or form. Tooth shape has an effect on cutting
rate.
Figure 56 – Blade Tooth Shape
The Regular, or standard blade, has evenly
spaced teeth that are the same size as the
gullets, and a zero-degree rake (i.e. cutting
angle). These offer precise, clean cuts at slower
rates. It is usually a good choice for cutting
curves and making crosscuts.
The Skip type has fewer teeth and larger gullets
with a zero rake. It allows faster cutting rates
than the Regular type, with a slightly coarser
finish. It is useful for re-sawing and ripping thick
stock, as well as cutting softwoods.
The Hook type blade has larger teeth and gullets
and a positive rake angle for more aggressive,
faster cutting when re-sawing or ripping thick
stock, especially hardwoods.
Variable-tooth blades combine features of the
other shapes, with tooth style and spacing
varying on the same blade. This produces
smooth cuts while dampening vibration.