Drill Bits Explained

Specialty Bits

While there are more specialty bits for wood than for other materials, each does a specific job.

A walk down the aisle of the drill bit section of the local home center can leave a shopper overwhelmed with the options of bits available. Drill bit packaging leaves a bit to be desired when determining what bit is perfect for what project. While there are more specialty bits for wood than for other materials, each does a specific job.

Auger Bits are used for drilling through logs or timber. This bit helps remove excess material from the hole as it drills through.

Brad Point Bits are used primarily for drilling holes in which a dowel will be inserted. The tip, called the brad point, allows for perfect centering in the item being drilled.

Counter Sunk Bits are the best choice when counter sunken screws are desired. While this can be done with a regular drill bit, a counter sunk bit will allow for consistent drilling in any wood product.

Forstner Bits are precision bits for drilling larger holes in wood. By choosing the correct Forstner bit, an exact size hole can be made for fitting tenons and other wood requirements. Most often used in drill presses, a sacrificial piece of wood should be placed under the material being drilled to create a smooth hole on both sides.

Hinge Bits, as the name implies, are used for precision drilling of holes in the proper place for attaching hinges to wooden objects such as boxes or doors.

Plug Cutter Bits are used to drill wooden plugs. Most often these plugs are used with counter sunk drill holes.

Spade Bits are used to rough cut large holes in wood or other soft materials.

Taper Bits are used in metalworking where perfect alignment is needed for precision metal parts requiring a tapered fastener.

Through Hole Bits are bits that allow coolant to flow through the bit. These are useful for flushing material when cutting precision metal parts.

Most specialty drill bits are available in a variety of metal alloys; each designed for a different purpose. These alloys can include high speed steel (HSS), carbide, cobalt and diamond. For most woodworking projects, high speed steel is sufficient, while metalworking may require carbide or other harder alloys.