of the rotating accessory which in turn causes the
uncontrolled power tool to be forced in the direction
opposite of the accessory'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 the 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.
The accessory may kickback over your hand.
c) Do not position your body in the area where power
tool will move if kickback occurs. Kickback will propel
the tool in the 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
or toothed saw blade. Such blades create frequent
kickback and loss of control.
3) SAFETY WARNINGS SPECIFIC FOR GRINDING AND
ABRASIVE CUTTING-OFF OPERATIONS
a) Use only wheel types that are recommended for
your power tool and the specific guard designed for
the selected wheel. Wheels for which the power tool
was not designed cannot be adequately guarded and
are unsafe.
b) The grinding surface of the centre depressed
wheels must be mounted below the plane of the
guard lip. An improperly mounted wheel that projects
through the plane of the guard lip cannot be adequately
protected.
c) The guard must be securely attached to the power
tool and positioned for maximum safety, so the least
amount of wheel is exposed towards the operator.
The guard helps to protect the operator from broken
wheel fragments, accidental contact with wheel and
sparks that could ignite clothing.
d) Wheels must be used only for recommended
applications. For example: Do not grind with the side of
a cut-off wheel. Abrasive cut-off wheels are intended for
peripheral grinding; side forces applied to these wheels
may cause them to shatter.
e) Always use undamaged wheel flanges that are of
correct size and shape for your selected wheel.
Proper wheel flanges support the wheel thus reducing
the possibility of wheel breakage. Flanges for cut-off
wheels may be different from grinding wheel flanges.
f) Do not use worn down wheels from larger power
tools. A wheel intended for a larger power tool is not
suitable for the higher speed of a smaller tool and may
burst.
4) ADDITIONAL SAFETY WARNINGS SPECIFIC FOR
CUTTING OFF OPERATIONS
a) Do not "jam" the cut-off 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.
b) Do not position your body in line with and behind
the rotating wheel. When the wheel, at the point of
operation, is moving away from your body, the possible
kickback may propel the spinning wheel and the power
tool directly at you.
c) When the 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 cut-off 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.
d) 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.
e) 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.
f) 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.
5) SAFETY WARNINGS SPECIFIC FOR SANDING
OPERATIONS
a) Do not use excessively oversized sanding disc
paper. Follow manufacturers recommendations,
when selecting sanding paper. Larger sanding paper
extending beyond the sanding pad presents a laceration
hazard and may cause snagging, tearing of the disc, or
kickback.
6) SAFETY WARNINGS SPECIFIC FOR WIRE
BRUSHING OPERATIONS
a) Be aware that wire bristles are thrown by the brush
even during ordinary operation. Do not overstress
the wires by applying excessive load to the brush.
The wire bristles can easily penetrate light clothing and/
or skin.
b) If the use of a guard is recommended for wire
brushing, do not allow any interference of the wire
wheel or brush with the guard. Wire wheel or brush
may expand in diameter due to work load and centrifugal
forces.
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