Bosch GSR18V-755C Operating/Safety Instructions Manual page 18

2610045251.qxp_GSB18V-755C GSR18V-755C 6/25/18 11:01 AM Page 18
pressure just before the bit breaks through the
wood. Then complete the hole from the back side.
DRILLING METAL
There are two rules for drilling hard materials. First,
the harder the material, the greater the pres sure
you need to apply to the tool. Second, the harder
the material, the slower the speed. Here are a
couple of tips for drilling in metal. Lubri cate the tip
of the bit occasionally with cutting oil except when
drilling soft metals such as alu minum, cop per or
cast iron. If the hole to be drilled is fairly large, drill
a smaller hole first, then enlarge to the required
size, it's often faster in the long run. Main tain
Before using an accessory,
be certain that its maximum
safe operating speed is not exceeded by the
nameplate speed of the tool. Do not exceed the
recommended wheel diameter.
SANDING AND POLISHING
Fine sanding and polishing re quire "touch". Select
the most efficient speed.
When using polishing bonnets, alway be sure the
excess string that secures the bonnet is tucked
well within the bonnet during operation.
WIRE BRUSHES
Work with brushes requires high speeds.
BRUSHING PRESSURE
1. Let the tips of a wire brush do the work.
Operate the brush with the lightest pressure so
only the tips of the wire come in contact with the
work.
2. If heavier pressures are used, the wires will
be overstressed, resulting in a wiping action;
and if this is continued, the life of the brush will
be shortened due to wire fatigue.
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enough pressure to assure that the bit does not
just spin in the hole. This will dull the bit and greatly
shorten its life.
Soft materials such as brick are relatively easy to
drill. Concrete however, will require much more
pressure to keep the bit from spinning. Be sure to
use carbide tip bits for all masonry work.
3. Apply the brush to the work in such a way
that as much of the brush face as possible is in
full contact with the work. Applying the side or
edge of the brush to the work will result in wire
breakage and shortened brush life.
INCORRECT: Excessive pressure can cause wire breakage.
SAVE THESE INSTRUCTIONS
DRILLING MASONRY
CORRECT: Wire tips doing the work.