11
7. MAKE PROPER TOOTH SELECTION
For maximum cutting efficiency and lowest
cost per cut, it is important to select the blade
with the right number of teeth per inch (TPI) for
the material being cut. The material size and
shape dictate tooth selection.
TOOTH
SELECTION
You need to consider:
The width of the cut -
That is, the distance in
the cut that each tooth must travel from the point
it enters the work-piece until it leaves the work-
piece, and
1.The shape of the work-piece.
Squares, Rectangles, Flats
(Symbol :
■
)
Locate the width of cut on the chart.
(Inches on the outer circle and
millimeters on the inner circle.) Select
the tooth pitch on the ring marked with
the square shape which aligns with
the width of cut.
EXAMPLE: 6" (150mm) square, use a
2/3 Vari-Tooth.
Round Solids (Symbol : ●)
Locate the diameter of your work-
piece on the chart. Select the tooth
pitch on the ring marked with the
round shape which aligns with the size
of stock you are cutting.
EXAMPLE: 4" (100mm) round, use a
3/4 Vari-Tooth.
Tubing, Pipe, Structural ( Symbol :
O H ^ )
Determine the average width of cut by
dividing the area of the work-piece by
the distance the saw blade must travel
to finish the cut. Locate the average
width of cut on the chart. Select the
tooth Ditch on the ring marked with
the tubing and structural shape, which
aligns with the average width you are
cutting.
EXAMPLE: 4"(100mm) outside diameter,
3"(75mm) inside diameter tubing.
4"(100mm) OD =12.5 sq.ln. (79cm
2
)
3"(75 mm ) ID = 7.0 sq.ln. (44cm
2
)
Area = 5.5 sq.ln. (35cm
2
)
5.5 sq.ln. (35cm
2
) / 4" (100mm)
distance =1.38(35mm) average width
1.38" (35mm), use a 4/6 Vari-
Tooth
NOTE:
The band speed and cutting
rate recommendations presented on
this chart are approximations and are
to be used as a starting point for most
applications. For exact sawing
parameters' consult your saw blade
supplier.
8. BI-METAL SPEEDS AND FEEDS
These figures are a guide to cutting 4"(100mm)
material (with a 314 Vari-Tooth) when using a
cutting fluid.
Increase Band Speed: 15% When cutting
1/4"(6.4mm) material (l0/l4 Vari-Tooth)
12% When cutting
3/4"(19 mm) material (6/10 Vari-Tooth)
10% When cutting 1-
1/4"(32 mm) material(5/8 Vari-Tooth)
5% When cutting 2-
1/2" (64 mm) material(4/6 Vari-Tooth)
Decrease Band Speed:
12% When cutting
8"(200mm) material(2/3 Vari-Tooth)
MATERIAL
ALLOY
ASTM NO.
BAND SPEED
FT./MIN M/MIN
Copper
Alloy
173,932
314
96
330,365
284
87
623,624
264
81
230,260,272
244
74
280,264,632,655 244
74
101,102,110,122,
172
234
71
1751,182,220,51
0
234
71
625,706,715,934 234
71
