Properties of Drill Bits

A drill bit is the detachable component of a drill used to cut a cylindrical hole. Drill bits can be used for different materials and are made of various strengths and sizes, depending on their application. There is a different drill bit for wood, metal/steel and concrete. They each have the same basic properties other than the tip, which is specifically made for the particular drilling material.

The "shank" is the end of the drill bit that attaches into the drill itself. A hammer drill typically will require a carbide-tipped drill that has grooves in the shank that allows it to fit in the drill collar. The Concrete Fastening Systems, an Ohio-based company that sells concrete fasteners and drill bits, describes the carbide-tipped drill bit as having grooves; two of those prevent the bit from falling out of the drill, the other larger grooves guide the bit to move in a positive rotation. These larger grooves also force the bit farther into the chuck of the drill and give more strength and torque when drilling.

The "land" or the raised area is the spiral end on a twist drill bit. The most common type of drill bit is the twist or metal cutting bit. Concrete Fastening Systems mentions the land section as being similar to the crest or peak of a wave. The driving axial forces of the bit in the power or hand drill are what give the drilling action.

The "flute" of the drill bit is the section of the spiral that is indented. The flutes remove the dust and small materials while the hole is drilled. The common twist bit usually has two flutes that wrap around the body of the bit. Not all drill bits have the spiral ends with a land and flute. There are flat wood drill bits (paddle or spade bits) and center drill bits that are designed a little different depending on the material it is used for.

The "head" and the "tip" of the drill bit work together to give more power and cutting capabilities. Choose the proper drill bit for the application material specifications to get the best results. Each tip is designed and created with appropriate components for the application. For example, the carbide tipped drill bit is made with a carbide head and tip to ease in drilling through concrete. (Reference 1)

Drill bits used for metal/steel or concrete are usually made of high speed steel (HSS). According to drillingbits.net, the HSS bits are made up of alloys of molybdenum, chromium, tungsten, vanadium and cobalt and small amounts of carbon. These components allow the drilling of metals without overheating. Carbon steel is another material some drill bits are made of and usually used for wood or plastic drilling applications. Many drill bits are coated with titanium nitride to increase the hardness of the bit and keep it lubricated during drilling.