Bosch 33614 Operating Instructions Manual page 11

BM 2610916919 7/02 7/11/02
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. 5
Second, unclamp the pieces and drill the
second hole the same diameter as the screw
shank in the first or top piece of wood.
Third, if flat head screw is used, countersink
the hole to make the screw flush with the
surface. Then, simply 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.
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 materials.
CARBIDE TIPPED BITS: Used for drilling
stone, concrete, plaster, cement and other
unusually hard nonmetals. Use continuous
heavy feed pressure when employing carbide
tip bits.
DRILLING WOOD
Be certain workpiece is clamped or anchored
firmly. Always apply pressure in a straight line
12:18 PM Page 11
with the drill bit. Maintain enough pressure to
2. Drill same dia-
meter as
keep the drill "biting".
screw shank.
When drilling holes in wood, twist bits can be
3. Countersink
used. Twist bits may overheat unless pulled
same diameter
as screw head. out frequently to clear chips from flutes.
Use a "back-up" block of wood for work that is
Adjustable
Screw
likely to splinter, such as thin materials.
Drill
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.
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. Here are a couple of tips for drilling in
metal. Lubricate the tip of the bit occasionally
with cutting oil except when drilling soft metals
such as aluminum, copper 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. Maintain enough
pressure to assure that the bit does not just
spin in the hole. This will dull the bit and greatly
shorten its life.
DRILLING MASONRY
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.
WARNING
!
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 require "touch".
Select the most efficient speed.
When using polishing bonnets, always be sure
the excess string that secures the bonnet is
tucked well within the bonnet during operation.
-11-
DRILLING METAL
Before using an accessory,
be certain that its maximum