Using Rotary Percussion Core Bits
Core Bits are useful for drilling large or long holes
in concrete. MILWAUKEE Heavy-Duty Core Bits
have heat-treated steel bodies with durable carbide
tips. These core bits are specially designed for fast,
accurate drilling with combined hammering and
rotary action.
1. Clean and lubricate the
threads on the adapter
and core bit to make
later removal easier.
Thread the adapter
shank to the rear of the
core bit.
2. Push the guide plate
onto the pointed end of
the center pin. Insert the
center pin and guide
plate assembly into the
core bit. Be sure the
small end of the center
pin is securely placed
into the hole in the cen-
ter of the core bit.
F o r L H S s y s t e m s ,
screw the threaded end
of the centering bit into
the core bit.
NOTE: If using an extension, first thread the
adapter shank to the extension. Then thread the
core bit to the extension.
3. Insert the adapter into the nose of the tool as
described in "Installing Bits and Chisels". Set the
knob to the "hammering with rotation" setting.
4. Press the centering bit
firmly against your cen-
ter mark, hold the tool
firmly and pull the trig-
ger.
N O T E :
I f
48-20-5099 threaded
stud is used, or a cen-
ter pin and guide plate
are not available, use
a template or notched
board to start the hole.
5. Start the tool. After drill-
ing to about the depth
of the core bit teeth,
remove the center pin
and guide plate from
the core bit (not nece-
sary for LHS system).
Resume drilling.
6. To change the core bit,
hold the tool upwards, pointing it away from your
body, and run it briefly in forward to loosen the
core bit from the adapter.
NOTE: To make deeper holes, remove the core bit,
break and remove the core, then resume drilling.
When drilling long or deep holes, after each inch
of penetration pull the bit partially out of the hole
while the tool is running, to help clear dust from
the bit flutes. Dust can clog the bit flutes and can
make the bit bind in the hole. If this occurs, stop
the tool, free the bit and begin again.
t h e
Drilling Large Diameter Holes
with Core Bits
When drilling holes with large diameter core bits,
dust may build up in the cut and can cause the tool
to stall, bind, or cut slowly. By creating an opening
for the dust to escape, drilling time, bit stress, and
tool stress can be reduced.
1. Start the cut as normal.
2. Once the bit is firmly established in
the cut (about 1/4" deep), remove
the bit from the cut.
3. Remove the bit from the tool.
4. Install a standard fluted bit, ap-
proximately 7/8" in diameter, onto
the tool.
5. Drill a perpendicular hole through
the kerf of the large hole.
• Depending on the location of the
work, the hole should either break
through the other side of the hole/
floor or extend 4"-5" past the end
Cut
of the workpiece (such as into the
approximately
dirt below a concrete slab).
1/4" deep with
• If dust builds up in the hole, vac-
a core bit.
uum it out and continue drilling.
• If drilling through a wall, the hole
for dust should be drilled on
the lowest part of the large
hole kerf as the dust will fall
there when drilling and can be
evacuated more easily.
6. Reinstall the core bit and con-
tinue drilling. Dust and debris
will fall through the hole and
optimize the cutting ability of
the bit.
NOTE: If unable to drill a hole
in the kerf, pull back on the bit
with the hammer running. This
will remove some of the dust
and debris from the cut. Repeat
this for every inch of drilling. If
necessary, vacuum dust and
debris from the cut and sur-
rounding area.
7. For core bits, once the maximum
core bit depth is drilled, the core
must be broken and removed.
• Install a chisel bit.
• Place the chisel into the hole
kerf.
• Chisel down into the kerf at
several points until the core is loose or broken.
• Remove the core and vacuum/remove any re-
maining dust and debris.
• Install the core bit and continue the cut.
6
Cut
approximately
1/4" deep with
a core bit.
Cut
Drill a hole
approximately
through the
1/4" deep with
work.
a core bit.
Top view
Drill a hole
through the
work.
Dust and debris
Dust and debris
will fall through
will fall through
the hole.
the hole.
Pull bit out as far
as possible once
or twice per inch
drilled.
D
th
T
Dus
will
Side view
of slab