Bosch GSB18V-535C Operating And Safety Instructions Manual page 16

2610045250.qxp_GSB18V-535C 6/20/18 10:26 AM Page 16
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.
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
to fasten materials together using your drill
without stripping, splitting or separating the
material.
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.
16
Operating Tips
DRILLING
Fig. 13 will enable you
SAVE THESE INSTRUCTIONS
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
Apply a slight
even pressure
when driving
screws
FIG. 13
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.
DRILLING WOOD
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 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
2. Drill same diameter
as screw shank
3. Countersink
same diameter
as screw head
Adjustable
Screw
Drill
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