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Parts & Service: 020 8988 7400 / E-mail: Parts@clarkeinternational.com or Service@clarkeinternational.com

DRILLING TIPS

• Always use sharp, good quality drill bits. The performance of your drill is

dependant on the quality of the bits used.

• After drilling material to the full depth, do not simply pull out the drill but

maintain chuck rotation to ease withdrawal.

• Reduce the pressure on the drill bit when it is about to break through. This will

prevent the drill from jamming.

• If drilling a large hole, first drill a pilot hole using a smaller drill bit.

• Always apply pressure to your drill bit in a straight line and, where possible, at

right angles to the workpiece.

• When drilling in metal, the materials being drilled can become hot. To reduce

overheating use a suitable cooling lubricant. No cooling lubricant is necessary

when drilling cast iron or brass as they should be drilled dry.

• When drilling metal, the harder the metal the slower the drill speed. Similarly,

the bigger the drill bit the slower the speed.

• To prevent the drill bit from slipping when starting to drill a hole in metal, use a

centre punch to make an indentation at the start point.

• Always start drilling at a slow speed to prevent the drill from slipping out of the

pop mark or indent, gradually increasing speed until the optimum cutting speed

is achieved whilst maintaining a MODERATE pressure ONLY. NEVER force the

drill bit into the work. This will overheat the tip and cause it to dull very quickly.

• When drilling in wood, clamp a piece of scrap wood to the underside of the

material to avoid splintering.

• Large holes should be drilled with wood augers, flat wood bits or hole saws.