Skil 6239 Owner's Manual page 14

Drilling Wood
Be certain workpiece is clamped or anchored firmly. 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
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
the recommended wheel diameter.
Wire Brushes
Work with brushes requires high speeds.
Brushing Pressure
1. Remember, the tips of a wire brush do the work. Operate the brush with the lightest
pressure so only the tips of the wire come in contact with the work.
2. If heavier pressures are used, the wires will be overstressed, resulting in a wiping action;
and if this is continued, the life of the brush will be shortened due to wire fatigue.
3. Apply the brush to the work in such a way that as much of the brush face as possible is in
full contact with the work. Applying the side or edge of the brush to the work will result in
wire breakage and shortened brush life.
CORRECT: Wire tips doing the work.
14
Before using an accessory, be certain that its maximum safe operating
speed is not exceeded by the nameplate speed of the tool. Do not exceed
15°
INCORRECT: Excessive pressure can
cause wire breakage.