Broken Drill Bit Extractor Info

Causes

• Drill bits can break off from the drill for several reasons. Cheaply manufactured drill bits might not be able to handle the pressure and will split off at the weakest point. Flexing the bit while drilling also puts too much pressure on it. Dull drill bits don't bite into the wood or concrete well, causing drag that equals too much pressure. Some drill bits must remain lubricated as they work; dry drill bits can result in too much force. Any time the drill bit encounters too much stress, the bit can break.

About Extractors

• Extractors are long pieces of strong metal with threads designed to grip the inside of metal. They are forced inside broken screws, bolts and drill bits, where the threads bite into the metal. A T-handled tap wrench allows you to grip the head of the extractor and twist, which brings the broken piece out with it. Screw extractors come in a variety of sizes, from one-eighth inch to half inch for thick bolts. Extractor bits frequently are sold in kits that include multiple drill bits.

Pilot Hole

• To extract a buried, broken drill bit, prepare it to accept a drill bit extractor. This requires drilling a pilot hole right through the center of the broken bit. Use a small drill bit for this, usually no more than one-sixteenth of an inch. Place the small drill bit directly into the center of the broken drill bit. Drill straight in -- the pilot hole must be centered exactly within the broken drill bit. Drill to the depth specified in the instructions that came with the drill extractor, but it should not be deeper than the drill bit itself or the extractor might not work.

Extracting Method

• Place the extractor into the pilot hole and tap it into place with a hammer. With a T-handled tap wrench on the extractor, twist the extractor counterclockwise to bury it tightly. From inside of the drill bit, it will give you the leverage you need to unscrew the broken drill bit from the wood or concrete. Turn the extractor counterclockwise until it lifts the broken drill bit out of the material.