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Wood Drilling
For maximum performance, use high-speed
steel or brad-point bits for wood drilling.
a. Begin drilling at a very low speed to prevent
the bit from slipping off the starting point.
b. Increase speed as the drill bit bites into the
material.
c. When drilling "through" holes, place a block
of wood behind the workpiece to prevent
ragged or splintered edges on the back side
of the workpiece (Fig. 12).
Bits may overheat unless they are
NOTICE
reversed and pulled out frequently
to clear chips from the flutes.
Metal Drilling
For maximum performance, use high-speed steel bits for metal or steel drilling.
a. When drilling metals, use light oil on the drill bit to keep it from overheating. The oil will
prolong the life of the bit and increase the drilling efficiency.
b. Begin drilling at a very low speed to prevent the bit from slipping off the starting point.
c. Maintain a speed and a pressure that allow cutting without overheating the bit. Applying too
much pressure will:
Overheat the drill.
–
Wear the bearings.
–
Bend or burn bits.
–
Produce off-center or irregularly shaped holes.
–
18
Fig . 12
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