Skil 3320-01 Depth scale method Fig, General Drilling Guidelines, Drilling speeds, Drilling metal

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workpiece and throw it, causing serious injury. The drill bit will break if the metal piece suddenly hits the column.

• If the metal is flat, clamp a piece of wood under it to prevent turning. If it cannot be laid flat on the table, then it should be blocked and clamped.

Drilling wood

• Brad point bits are preferred. Metal piercing twist bits may be used on wood.

• Do not use auger bits. They turn so rapidly that they lift the workpiece off the table and whirl it around.

• Always protect the drill bit by positioning the table so the drill bit will enter the center hole when drilling through the workpiece.

• To prevent splintering, feed slowly when the bit is about to cut through to the backside of the workpiece.

• To reduce splintering and protect the point of the bit, use scrap wood as a backing or a base block under the workpiece. Feeding the bit

• Pull down on the feed handles with only enough force to allow the drill bit to cut.

• Feeding too rapidly might stall the motor, cause the belt to slip, damage the workpiece, or break the drill bit.

• Feeding too slowly will cause the drill bit to heat up and burn the workpiece.

		Operation (continued)
1.	Depth scale method (Fig. 30)		FIG. 30
	With the switch	(1) OFF, turn the feed handle (2) until
	the drill bit tip	(3) slightly touches the top of the	5
2.	workpiece (4).
	Hold the feed handles in that position.		1
3.	Loosen the depth lock knob (5).
4.	Spin the depth scale hub (6) until the desired drilling
5.	depth is at the scale pointer.		6
	Lock the depth lock knob. The chuck and drill bit will			2
	now drill into the workpiece only to the distance
	selected on the depth scale.		3

General Drilling Guidelines

!To reduce the risk of injury, make sure the chuck key is removed from

the chuckWARNINGbefore starting any drilling operation.

Drilling speeds

Important factors when determining the best drilling speed:

• Type of material

• Size of the hole to be drilled

• Type of drill bit or cutter

• Desired quality of the cut

Remember, smaller drill bits require greater speed than large drill bits. Softer materials require greater speed than harder materials.

Drilling metal

• Use metal-piercing twist drill bits.

• It is always necessary to lubricate the tip of the drill with oil to prevent overheating the drill bit.

• All metal workpieces should be clamped down securely. Any tilting, twisting, or shifting causes a rough drill hole, and increases the potential of drill bit breakage.

• Never hold a metal workpiece with your bare hands. The cutting edge of the drill bit may seize the 19.