-42-
For Machines Mfd. Since 7/21
South Bend Tools
Model SB1123
O P E R A T I O N
Blade Breakage
Many conditions may cause a bandsaw blade to
break. Blade breakage is unavoidable in some
cases, since it is the natural result of the peculiar
stresses that bandsaw blades are subjected to.
Blade breakage is also due to avoidable
circumstances. Avoidable blade breakage is most
often the result of poor care or judgement on the
part of the operator when mounting or adjusting
the blade or support guides.
The most common causes of blade breakage
are:
• Faulty alignment or adjustment of the blade
guides.
• Forcing or twisting a wide blade around a
short radius.
• Feeding the workpiece too fast.
• Dull or damaged teeth.
• Over-tensioned blade.
• Upper blade guide assembly set too high
above the workpiece. Adjust the top
blade guide assembly so that there is
approximately
1
⁄
8
"–
1
⁄
4
" between the bottom of
the assembly and the workpiece.
• Using a blade with a lumpy or improperly
finished braze or weld.
• Leaving the blade tensioned when not in use.
• Using the wrong pitch (TPI) for the
workpiece thickness. The general rule of
thumb is to have no less than two teeth
in contact with the workpiece at all times
during cutting.
Blade Care & Break-In
Blade Care
A bandsaw blade is a thin piece of steel that is
subjected to tremendous strain. You can obtain
longer use from a bandsaw blade if you give it
fair treatment and always use the appropriate
feed rate for your operation.
Be sure to select blades with the proper width,
set, type, and pitch for each application. Using
the wrong blade will produce unnecessary heat
and shorten the life of the blade.
A clean blade will perform much better than
a dirty blade. Dirty or gummed up blades
pass through the cutting material with much
more resistance than clean blades. This extra
resistance also causes unnecessary heat.
Blade Break-In
The tooth tips and edges of a new blade are
extremely sharp, and cutting at too fast of a feed
rate fractures the beveled edges of the teeth and
causes premature blade wear.
To properly break in a new blade:
1.
Choose correct speed for blade and material
of operation.
2.
Reduce feed pressure by half for first
50–100 in
2
of material cut.
3.
To avoid twisting blade when cutting, adjust
feed pressure when total width of blade is in
cut.
