BM 2609140392 11/06 12/4/06 8:25 AM Page 16
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
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 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 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.
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.
INCORRECT: Excessive pressure can cause wire breakage.
RUNNING NUTS AND BOLTS
Variable speed control must be used with caution for driving nuts and bolts with socket set attachments. 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.