A bore drill bit is a tool used for cutting cylindrical holes in a variety of materials such as wood, drywall and metal. It does this by rotating the bit attached to the drill to cut a hole into the surface of the material. This bit can drill holes in a wide range of sizes from a diameter of 1/4 inch (0.635 cm) to 6 inches (15.24 cm). It drills quickly and efficiently, even in hard wood or metal. The bit is usually attached or held by a drill which rotates the bore drill bit with enough torque and axial force to cut a hole into the material being drilled.
Two parts make up a bore drill bit — namely the shank, which is the part held by the drill, and the cutting edge, which enters the material being drilled. They normally come in different sizes which correspond to various sizes of holes they will drill. Most outlets selling drills will have a size chart to help the buyer determine the exact size to purchase.
The geometrical structure of a bore drill bit can further be described in numerous ways. The spiral of a drill bit refers to its rate of twist, which determines the rate at which it removes chips from the drilled material. There are fast spiral drills for drilling materials like wood and slow spiral drills for applications that require it, such as drilling aluminum.
The point angle of a drill refers to the angle at its tip. Generally, the point angle of a bore drill bit depends on the kind of material being drilled. For example, harder materials can best be drilled using a bit with a larger point angle while softer materials are drilled using bits with a sharper angle. The amount of force applied on the drill bit’s cutting edge is usually determined by the bit’s lip angle. A bigger lip angle ensures a more aggressive drilling.
Choosing a bore drill bit that is appropriate to the task can sometimes be confusing. The purchaser simply needs to understand the types of bore drill bits on the market, however. A few examples of these types include the twist drill bit, used to cut small holes in both wood and metal; the spade drill bit, used to cut holes of up to 1.5 inches (3.81 cm) in wood; and the expansion bore drill bit, for drilling wide 3 inch (7.62 cm) diameter holes in wood.