POWER TOOLS IDENTIFICATION AND

SAFETY

Created by Gary W. Adams,

Canyon Lake High School

PORTABLE ELECTRIC DRILL

Chapter 9

The portable electric drill is used to pierce metal, wood, plastics, and other materials.

The size of the portable drill is determined by the largest diameter drill shank that can be inserted into the chuck.

The most common chuck sizes are 1/4”, 3/8” and 1/2”. Portable drills can be selected according to size, motor rating, whether or not reversible, single or variable speed, and type of use

Pre-Use Check

Thoroughly review and understand information provided in the portable power drill operator’s manual with particular attention given to descriptions of safety procedures.

Before using, always inspect the portable power drill for damage or disrepair. In addition, assure the drill chuck is functioning properly and as appropriate, inspect the electrical cord and plug or battery/battery pack

If the portable power drill fails your inspection, notify your supervisor and remove the portable power drill from service by attaching a red tag that states “DO NOT USE.” Complete red tag with appropriate information.

Procedure for Safely Operating the Portable Drill

Use only sharp twist drills; disconnect the power source when changing twist drills.

Tighten the chuck securely and remove the chuck key.

Use a center punch or awl to locate the center of the proposed hole.

Secure the stock, be sure the drill is properly grounded or double insulated, and that the cord is clear of the work area.

Hold the drill with both hands at the correct angle while applying a steady, even pressure. Be sure you have good footing and a firm grip. Never attempt to drill work held in your hand.

Withdraw the drill occasionally to clear the cuttings or chips.

Apply a coolant or lubricant when drilling metal

Ease off the pressure as the twist drill cuts through the stock to prevent splintering or grabbing.

Scrap stock can be clamped to the backside of the material being drilled to prevent splintering and grabbing.

Note: When drilling large diameter holes, it may be necessary to first drill a pilot hole.

Never wear a tie or loose clothing or jewelry when using a portable power drill. Tie long hair back or secure under a cap.

Always wear safety glasses or goggles when drilling.

Do not operate a portable power drill in the presence of flammable fumes.

Avoid using a portable electric drill when it is raining or in wet conditions.

Use the correct drill bit for the type of material to be drilled and task at hand.

Before inserting a battery or plugging in a portable power drill, turn the power switch off.

Make all portable power drill adjustments with the power switch off and the drill unplugged.

Insert bit into drill chuck and tighten with the chuck key. Remove chuck key from the drill chuck before starting the portable power drill.

Keep your hands and fingers away from the rotating drill chuck and bit.

Do not force a drill bit against the stock being drilled. If a drill bit is not penetrating properly, turn the drill off and change the drill bit.

Use caution when changing drill bits, as they are sharp and can become hot during use.

Only recharge a portable power drill battery or battery pack with a battery charger recommended by the manufacturer.

Always use the type of battery or battery pack specified for the portable power drill.

Never carry a portable power drill by the power cord.

When carrying a portable power drill, turn the drill off and keep your index finger away from the power switch.

Never stop the rotation of the drill chuck or bit with your hands or fingers.

Always clean your work area upon completion of the drilling task.

Drilling Metal

Determine the center of the hole and mark it with a center punch to keep the drill from crawling.

Clamp small stock in a drill press vise (general purpose, angle, rotary indexing table, or universal compound vise). A strap clamp for flat stock and V-block for round material are recommended for small stock. V-blocks are sometimes used with Y-clamps. C-clamps and angle iron also make good stock supports, especially if the metal is irregular in shape. Parallels and strap clamps are fastened to the table with special fasteners.

Use a good grade of cutting oil while drilling. It cools cutting lips and stock, lubricates chips, improves the finish of holes, and lengthens the life of drills. Kerosene can be used on dense aluminums. Some nonferrous metals are drilled without the use of oil.

Drilling metal is similar to drilling wood in that a steady; even pressure is applied until the bit begins to break through the metal when drilling holes. Most ferrous metals will produce ribbons or rolled chips, instead of small chips, if proper pressure is applied. Chips will appear when drilling cast iron. Use a brush to remove these chips from the table, not your fingers.

Other Drill Press Operations

Reaming and Lapping - Reaming is the removing of a small amount of metal to increase the size of an existing hole. Lapping a surface is done with a rod and abrasive. It is more like polishing than cutting metal.

Plastic and Glass Drilling - Special bits are used to drill both plastic and glass. Plastic holes should be slightly oversize. Glass is drilled with either a diamond-tip or tungsten carbide tipped bit. Glass is placed on a flat surface and the proper amount of pressure is applied, and kerosene, water, or turpentine is used as a lubricant while drilling.

Metal Finishing and Shaping - There are several different types of shaping, de-burring, and grinding points used to shape metal. Cutters and grinders are used to shape metal, plastic, and wood. The quill is locked at the proper height, and the stock is pushed against the cutter or grinder lightly. The quill is also locked in the proper position when using wire brushes or buffers.

Drill Motor Parts

Drill Motor Types

Chuck Key

Chuck

Keyless Chucks

Twist Drill Bits

Step Bits

Twist bit With Pilot Point

Wood Auger Bit

Glass Bit

Mason bit

Round Shanks

Taper Shank

Off Set Shank

Brace with bits

Pre Test

Sleeves should be rolled up; ties, watches and rings should be removed; and safety glasses should be worn while operating the electric drill.True

Be sure the drill is double insulated or safetly grounded before operating it.True

Never operate the portable drill while standing in water or on wet floor.True

Use the forefinger to brush chips from around the twist drill bit.False

Always lock the switch in the on position when using the portable drill.False

The twist drill will not run turn if the chuck is not properly tightened.False

Stock should be securely fastened to prevent twisting during the drilling process.True

The drill should be pulled across the floor by the power cord.False

The center of the hole to be drilled should be marked with a center punch or an awl.True

Drill with even, steady pressure and let the drill to the workTrue

When drilling deep holes withdraw the drill bit from the hole several times to clear out the chips.True

When using a large drill, brace the body well to prevent injuryTrue

Twist drill are made and sharpened to cut in a clockwise direction.True

Power should be disconnected and the twist drill(bit) should be removed from the chuck as soon as the work is complete.True

It is permissible to operate the portable drill with the chuck key in the chuck.False

A twist drill (bit) is designed to cut a hole in metal not wood, but can be used in wood.True

A true wood bit with a round shank can be used in a portable drill motor.True

A spade bit is not made for a portable drill motor.False

Another name for the geared key chuck is a 3-jawed Jacob Chuck.True

The safety rules apply to all drills even cordless drill motors.True

The big ½ inch chucked drills are larger and more dangerous because they can bind or hang up and the motor torque can break a wrist or forearm easily.True

Apply a coolant or lubricant when drilling metalTrue

Ease off the pressure as the twist drill cuts through the stock to prevent splintering or grabbing.True

Never wear a ties, loose clothing or jewelry when using a portable power drill. True

It is considered safe to operate a portable power drill in the presence of flammable fumes.False

Recharge a portable power drill batteries with the battery charger recommended by the manufacturer.True

Always use the type of battery or battery pack specified for the portable power drill.True

Never stop the rotation of the drill chuck or bit with your hands or fingers.True

Use only sharp twist drills; disconnect the power source when changing twist drills.True

Hold the drill with both hands at the correct angle while applying a steady, even pressure. Be sure you have good footing and a firm grip and never attempt to drill work held in your hand.True