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2610042685 DDH183 HDH183.qxp_DDH - HDH 1/22/16 12:26 PM Page 13
DRIVING NUTS AND BOLTS
Variable speed control must be used with
caution for driving nuts and bolts with socket
set attach ments. The technique is to start
slowly, increasing speed as the nut or bolt runs
down. Set the nut or bolt snugly by slowing the
drill to a stop. If this procedure is not followed,
the tool will have a tendency to torque or twist
in your hands when the nut or bolt seats.
DRILLING
You will extend the life of your bits and do
neater work if you always put the bit in contact
with the work before pulling the trigger. During
the oper a tion, hold the tool firmly and exert
light, steady pressure. Too much pressure at
low speed will stall the tool. Too little pressure
will keep the bit from cutting and cause excess
friction by sliding over the surface. This can be
damaging to both tool and bit.
DRILLING WITH VARIABLE SPEED
The variable speed trigger allows you to slowly
increase RPM. By using a slow starting speed,
you are able to keep the bit from "wander ing".
You can increase the speed as the bit "bites"
into the work by squeezing the trigger.
DRIVING WITH VARIABLE SPEED
Variable speed drills will double as a power
screwdriver by using a screwdriver bit. Prior to
driving screws, pilot and clearance holes should
be drilled. Place the threaded end of the screw
in the pilot or clearance hole and start driving
the screw slowly, increasing the speed as the
screw runs down. Set the screw snugly by
slowing to a stop.
FASTENING WITH SCREWS
The procedure shown in Fig. 13 will enable
you to fasten materials together using your
drill without stripping, splitting or separating
the material.
DRILL BITS
Always inspect drill bits for excessive wear.
Use only bits that are sharp and in good
condition.
TWIST BITS: Available with straight and
reduced shanks for wood and light duty metal
drilling. High speed bits cut faster and last
longer on hard ma terials.
CARBIDE TIPPED BITS: Used for drilling
stone, con crete, plaster, cement and other
unusually hard nonmetals. Use continuous
heavy feed pres sure when employing carbide
tip bits.
Operating Tips
First, clamp the pieces together and drill the
hole 2/3 the diameter of the screw. If the
material is soft, drill only 2/3 the proper
length. If it is hard, drill the entire length.
Second, unclamp the pieces and drill the
hole in the top piece of wood again to the
same diameter as the shank of the screw.
Third, if flat head screw is used, countersink
the hole to make the screw flush with the
surface. Realign the holes on the two pieces
and apply even pressure when driving the
screw. The screw shank clearance hole in
the first piece allows the screw head to pull
the pieces tightly together.
The adjustable screw drill accessory will do
all of these operations quickly and easily.
Screw drills are available for screw sizes No.
6, 8, 10 and 12.
FASTENING
WITH SCREWS
1. Drill 2/3 diameter and
2/3 of screw length for
soft materials, full
length for hard
materials.
Screw
Be certain workpiece is clamped or anchored
firm ly. Always apply pressure in a straight line
with the drill bit. Maintain enough pressure to
keep the drill "biting".
When drilling holes in wood, twist bits can be
used. Twist bits may overheat unless pulled out
frequently to clear chips from flutes.
Use a "back-up" block of wood for work that is
likely to splinter, such as thin materials.
You will drill a cleaner hole if you ease up on
the pressure just before the bit breaks through
-13-
2. Drill same
diameter as
screw shank.
3. Countersink
same diameter
as screw head.
Apply a slight
even pressure
when driving
screws.
FIG. 13
DRILLING WOOD
Adjustable
Screw
Drill
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