Stihl TSA 230 Instruction Manual page 21

8) Further safety instructions for
abrasive cutting-off operations
Kickback and related warnings
Kickback is a sudden reaction to a
pinched or snagged rotating wheel.
Pinching or snagging causes rapid
stalling of the rotating wheel which in
turn causes the uncontrolled power tool
to be forced in the direction opposite of
the wheel's rotation at the point of the
binding.
For example, if an abrasive wheel is
snagged or pinched by the workpiece,
the edge of the wheel that is entering
into the pinch point can dig into the
surface of the material causing the
wheel to climb out or kick out. The wheel
may either jump toward or away from the
operator, depending on direction of the
wheel's movement at the point of
pinching. Abrasive wheels may also
break under these conditions.
Kickback is the result of power tool
misuse and/or incorrect operating
procedures or conditions and can be
avoided by taking proper precautions as
given below.
a) Maintain a firm grip on the power
tool and position your body and arm
to allow you to resist kickback
forces. Always use auxiliary handle,
if provided, for maximum control
over kickback or torque reaction
during start-up. The operator can
control torque reactions or kickback
forces, if proper precautions are
taken.
b) Never place your hand near the
rotating accessory. Accessory may
kickback over your hand.
TSA 230
c) Do not position your body in line
with the rotating wheel. Kickback
will propel the tool in direction
opposite to the wheel's movement
at the point of snagging.
d) Use special care when working
corners, sharp edges etc. Avoid
bouncing and snagging the
accessory. Corners, sharp edges or
bouncing have a tendency to snag
the rotating accessory and cause
loss of control or kickback.
e) Do not attach a saw chain,
woodcarving blade, segmented
diamond wheel with a peripheral
gap greater than 10 mm or toothed
saw blade. Such blades create
frequent kickback and loss of
control.
f) Do not "jam" the wheel or apply
excessive pressure. Do not attempt
to make an excessive depth of cut.
Overstressing the wheel increases
the loading and susceptibility to
twisting or binding of the wheel in
the cut and the possibility of
kickback or wheel breakage.
g) When wheel is binding or when
interrupting a cut for any reason,
switch off the power tool and hold
the power tool motionless until the
wheel comes to a complete stop.
Never attempt to remove the wheel
from the cut while the wheel is in
motion otherwise kickback may
occur. Investigate and take
corrective action to eliminate the
cause of wheel binding.
h) Do not restart the cutting operation
in the workpiece. Let the wheel
reach full speed and carefully re-
enter the cut. The wheel may bind,
walk up or kickback if the power tool
is restarted in the workpiece.
i) Support panels or any oversized
workpiece to minimize the risk of
wheel pinching and kickback. Large
workpieces tend to sag under their
own weight. Supports must be
placed under the workpiece near
the line of cut and near the edge of
the workpiece on both sides of the
wheel.
j) Use extra caution when making a
"pocket cut" into existing walls or
other blind areas. The protruding
wheel may cut gas or water pipes,
electrical wiring or objects that can
cause kickback.
English
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