Bosch GWS 20-180 H Professional Manual Original página 17

accumulation of powdered metal may cause electrical
hazards.
Do not operate the power tool near flammable materi-
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als. Sparks could ignite these materials.
Do not use accessories that require liquid coolants.
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Using water or other liquid coolants may result in electro-
cution or shock.
Kickback and Related Warnings
Kickback is a sudden reaction to a pinched or snagged rotat-
ing wheel, backing pad, brush or any other accessory. Pinch-
ing or snagging causes rapid stalling of the rotating access-
ory 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 direc-
tion of the wheel's movement at the point of pinching. Abras-
ive 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.
Maintain a firm grip on the power tool and position
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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 reac-
tions or kickback forces, if proper precautions are taken.
Never place your hand near the rotating accessory.
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Accessory may kickback over your hand.
Do not position your body in the area where power
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tool will move if kickback occurs. Kickback will propel
the tool in direction opposite to the wheel's movement at
the point of snagging.
Use special care when working corners, sharp edges
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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.
Do not attach a saw chain woodcarving blade or
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toothed saw blade. Such blades create frequent kick-
back and loss of control.
Safety Warnings specific for Grinding and Abrasive
Cutting-Off operations
Use only wheel types that are recommended for your
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power tool and the specific guard designed for the se-
lected wheel. Wheels for which the power tool was not
designed cannot be adequately guarded and are unsafe.
The grinding surface of centre depressed wheels must
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be mounted below the plane of the guard lip. An im-
properly mounted wheel that projects through the plane
of the guard lip cannot be adequately protected.
The guard must be securely attached to the power tool
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and positioned for maximum safety, so the least
Bosch Power Tools
amount of wheel is exposed towards the operator.
The guard helps to protect operator from broken wheel
fragments, accidental contact with wheel and sparks that
could ignite clothing.
Wheels must be used only for recommended applica-
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tions. For example: do not grind with the side of cut-
off wheel. Abrasive cut-off wheels are intended for peri-
pheral grinding, side forces applied to these wheels may
cause them to shatter.
Always use undamaged wheel flanges that are of cor-
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rect size and shape for your selected wheel. Proper
wheel flanges support the wheel thus reducing the pos-
sibility of wheel breakage. Flanges for cut-off wheels may
be different from grinding wheel flanges.
Do not use worn down wheels from larger power
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tools. Wheel intended for larger power tool is not suit-
able for the higher speed of a smaller tool and may burst.
Additional Safety Warnings specific for Abrasive Cutting
Off operations
Do not "jam" the cut-off wheel or apply excessive
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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.
Do not position your body in line with and behind the
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rotating wheel. When the wheel, at the point of opera-
tion, is moving away from your body, the possible kick-
back may propel the spinning wheel and the power tool
directly at you.
When wheel is binding or when interrupting a cut for
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any reason, switch off the power tool and hold the
power tool motionless until the wheel comes to a com-
plete 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 ac-
tion to eliminate the cause of wheel binding.
Do not restart the cutting operation in the workpiece.
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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.
Support panels or any oversized workpiece to minim-
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ize 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.
Use extra caution when making a "pocket cut" into ex-
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isting walls or other blind areas. The protruding wheel
may cut gas or water pipes, electrical wiring or objects
that can cause kickback.
Safety Warnings specific for Sanding operations
Do not use excessively oversized sanding disc paper.
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Follow manufacturers recommendations, when select-
ing sanding paper. Larger sanding paper extending bey-
ond the sanding pad presents a laceration hazard and
may cause snagging, tearing of the disc, or kickback.
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1 609 92A 431 | (21.11.2018)