Useful Drill Accessories

Drill Accessories Safety Tips

When drilling with hole saws or large capacity bits, use a drill press or clamp the material to the table. If this is not possible, beware that the drill bits can bind in the material if the drill is not held exactly level with the hole. If the drill bit binds, it may stop moving, but the drill may continue to move, taking your hand with it.

Avoid burning the workpiece by drilling at slower speeds when using a hole saw or large capacity cutter.

Never try to free up a jammed drill bit by stopping and starting the drill.

Always unplug the drill before changing bits and accessories.

Always have secure footing when drilling. Carefully brace yourself when drilling on a scaffolding or ladder.

Always make sure the drill chuck is securely tightened around the spindle of the drill bit.

Twist Drill Bit

Used in both wood and unhardened metals to make clearance holes for bolts, screws, etc., and to make holes for tapping.

Bits marked HS (high speed) or HSS (high speed steel) are suitable for drilling in metals or wood,

Bits made of carbon steel should be used only in wood and not in metal as they are more brittle and less flexible than HSS bits.

Hole Saw

Cup-shaped blade with a bit in the middle, called a mandrel.

Used for cutting holes in wood, plastic, plaster and light metals.

Available in a range of diameters

Brad Point Bit

Used for wood drilling only.

Tip has a screw-type point leading the drill flute that prevents drill walking.

Helps prevent splintering, as the brad point is the first part of the drill to emerge, allowing the user to back the drill out of the hole and finish from the other side of the material.

Spade Drill Bit

Used in electric drills and drill presses for fast drilling of holes in wood.

Bits have a forged, flat paddle with a point and cutting edges on one end.

Bits are heat treated and cutting angles finish ground.

Electricians use them for drilling clearance holes for wire in floor beams.

Countersink Bits

Widen holes so flathead screws may be flush mounted below the surface for a finished appearance.

The counterbore is another version that makes a straight-walled hole so there’s room for a wooden plug.

Auger Drill Bit

Most commonly used with a brace for drilling holes in wood.

Length varies from 7" to 10".

Dowel bits are short auger bits from 5" long.

Long (ship) auger bits range from 12" to 30

Expansion Bit

Takes the place of many larger bits.

It is adjusted by moving the cutting blade in or out by a geared dial or by a lockscrew to vary the size of the hole

Masonry Bit

Also known as a carbide-tipped bit.

Used in electric drills, drill presses or hand drills for drilling holes in brick, tile, cement, marble and other soft masonry materials.

Some versions have a titanium nitride-coated tip.

Feature two machined in spiral threads, one for each cutting edge, to provide passageways for all dust and cuttings from the bottom of the hole.

Diameters of carbide tips are the same as the full diameter of the body.

Tile Bit

Used for drilling ceramic tile and glass.

Has a ground tungsten carbide tip.

Best if used with a variable speed power drill at a low speed.

Step Bit

Has a graduated design so that various sized holes can be cut without changing bits.

Designed for use with power drills and has self-starting tips eliminating the need for center punching. Can be used on all materials, but especially designed for use on metals

Circle Cutter

Also known as a fly cutter.

Has a cutting blade attached to a horizontal arm. It can cut holes up to 7” in diameter.

Primarily used on a drill press

Abrasive Attachments

There are a wide variety of attachments for drills that can be used for shaping or finishing metal. Others can be used for sanding and cleaning a variety of materials.

Buffers polish metal or furniture.

Abrasive discs can be used for grinding or sanding.

Wire wheels remove rust and paint, and some types can clean concrete, asphalt and plaster.

Disc and drum rasps quickly complete coarse sanding jobs.