-22-
Model T28366 (Mfd. Since 04/18)
To select correct blade pitch:
1. Measure thickness of workpiece.
— For solid workpieces, this measurement
is length of cut taken from where tooth
enters workpiece, sweeps through, and
exits workpiece. See (D) on chart in
Figure 28.
— For hollow or profiled workpieces, this
measurement is wall thickness at its thick-
est point (Th).
2. Refer to "D or Th" column of blade selection
chart in
Figure 28, and read down to find
workpiece thickness you need to cut. Read
across to find appropriate Pitch (TPI) for cut.
See
Accessories on Page 29.
0.5"
1"
2"
3"
4"
5"
0.02"
1/16"
3/32"
1/8"
3/16"
1/4"
6–8
4–6
3–4
2–3
2
.8-1.5
8–10
5–7
4–5
3.5–4
2
.8-1.5
Th
Th
Th
D
>7
6
7
5
4
3
2.5
<2.5
1/16 (2)
<1/16 (<2)
D or Th Inches (mm)
Pitch(TPI)
Workpiece
Measurements
1/8 (3)
1/4 (6)
1/2 (12)
1 (25)
2 (50)
3 (75)
>3 (>75)
O
Figure 28.
Blade selection chart.
Similarly, if the workpiece is a soft metal such as
aluminum, each tooth will remove more material
and rapidly fill the blade gullet. For this reason,
use a blade with fewer TPI on soft metals.
An additional problem with an overly fine-pitched
blade is that the pressure each tooth exerts on the
workpiece is reduced. This limits the cutting ability
of the teeth and also results in a buildup of heat
and inefficient cuts.
The ideal blade pitch is one that doesn't overload
individual teeth (too coarse) and avoids excessive
chip buildup in the gullet (too fine) (see
Figure 27).
Workpiece
Chips
Gullet
Blade
(Correct TPI
For Workpiece)
Figure 27.
Correct TPI.
Damage to the blade, rough cuts, poor cutting
performance, and overheating are all possible
signs of improper blade pitch.
If you feel your machine is not functioning properly
or performing to your standards, check that the
blade pitch is correct for the cut. The procedure
that follows is a basic starting point for choosing
blade pitch (TPI) for standard HSS blades.