DRILLING MASONRY
(HAMMER DRILLING MODE)
For maximum performance, use carbide-tipped
masonry bits when drilling holes in brick,
concrete, etc. and set the mode selector to the
hammer drilling mode
a. Maintain a speed and a pressure that allow
cutting without overheating the bit or drill.
Applying too much pressure will:
Overheat the drill.
–
Wear the bearings.
–
Bend or burn bits.
–
DRILLING
WARNING
with side shields during power tool
operation or when blowing dust. If operation
is dusty, also wear a dust mask.
a. Check that the direction-of-rotation selector is
at the correct setting (forward or reverse).
b. Secure the material to be drilled in a vise or
with clamps to keep it from turning as the drill
bit rotates.
c. Hold the drill firmly and place the bit at the
point to be drilled.
d. Depress the variable-speed trigger switch to
start the drill.
e. Move the drill bit into the workpiece, applying
only enough pressure to keep the bit "biting".
Do not force the drill or apply side pressure to
elongate a hole. Let the tool do the work.
f. When drilling hard, smooth surfaces, use a
center punch to mark the desired location of
the hole. This will prevent the drill bit from
slipping off-center as the hole is started.
.
Always wear safety
goggles or safety glasses
Produce off-center or irregular-shaped holes.
–
b. Apply light pressure and medium speed for
best results in brick.
c. Apply additional pressure for hard materials,
such as concrete.
d. Begin drilling at a very low speed to prevent
the bit from slipping off the starting point.
g. When drilling metals, use light oil on the drill
bit to keep it from overheating. The oil will
prolong the life of the bit and increase the
drilling action.
h. If the bit jams in the workpiece or if the drill
stalls, stop the tool immediately. Remove the
bit from the workpiece and determine the
reason for jamming.
There are two rules for drilling hard materials.
First, the harder the material, the greater the
pressure you need to apply to the tool. Second,
the harder the material, the slower the speed
should be. If the hole to be drilled is fairly large,
drill a smaller hole first, and then enlarge to the
required size with a larger bit; it's often faster in
the long run.
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