Black & Decker 7154 - Manual (Page 4)

4. OPERATION
B/ack & Decker
1
DRILLING
1. Always unplug the Drill when attaching or changing bits or acces­
sories.
2. Use sharp drill bits only. For WOOD, use twist drill bits, spade bits,
power auger bits, or hole saws. For METAL, use high-speed steel
twist drill bits or hole saws. For MASONRY, such as brick, cement,
cinder block, etc., use carbide-tipped bits.
3. Be sure the material to be drilled is anchored or clamped firmly.
If drilling thin material, use a wood “back-up” block to prevent
damage to the material.
4. Center-punch an indentation at the point to be drilled. This will
overcome the tendency of the bit to slip around on a smooth surface.
Place the tip of the bit in the indentation and turn motor “ON”.
NOTE; With Variable Speed Drills, holes can be started at low speed
without the need for center punching.
5. Always apply pressure in a straight line with the bit. Use enough
pressure to keep drill biting, but do not push hard enough to stall
the motor or deflect the bit.
6. Hold drill firmly to control the twisting action of the drill.
7. IF DRILL STALLS, it is usually because it is being overloaded or
improperly used. RELEASE TRIGGER IMMEDIATELY, remove drill bit
from work, and determine cause of stalling. DO NOT CLICK TRIGGER
OFF AND ON IN AN ATTEMPT TO START A STALLED DRILL — THIS
CAN DAMAGE THE DRILL.
8. To minimize stalling on breaking through the material, reduce
pressure on drill and ease the bit through the last fractional part
of the hole.
9. Keep the motor running when pulling the bit back out of a drilled
hole. This will help prevent jamming.
DRILLING IN METAL
Use a cutting lubricant when drilling metals. The exceptions are cast iron
and brass which should be drilled dry. The cutting lubricants that work
best are sulphurized cutting oil or lard oil; bacon grease will also serve
the purpose. Aluminum is best drilled with kerosene.
DRILLING IN WOOD
Holes in wood can be made with the same twist drills used for metal.
These bits may overheat unless pulled out frequently to clear chips from
the flutes. For larger holes, use Power Drill Wood Bits. Work that is apt
to splinter should be backed up with a block of wood.