When it is time to bore a hole, a drill bit attached to the end of a power drill is often the most efficient method. Bits need to be selected to match both the job and the material. While there are special types that do not fall into traditional measuring standards, most are made in either standard or metric sizes. Most bits are used to make round holes, but some of the special ones create various shapes.
The most common type in use today is the twist bit. It can be used to bore holes in metal, wood, and plastic depending on the angle and fluting of the bit. Twist bits are commonly available in many sizes, from the tiny ones with a diameter of about two thousandths of an inch to those with a diameter approaching four inches. Lengths for home use can reach almost forty inches.
Cutting Bits
Center bits often are used for metals to make a starter hole that will be drilled with a larger bit. However, the true purpose of center bits is to make an indentation for a lathe. Spotting bits are actually the preferred choice for starter holes.
When the job calls for enlarging a hole that already exists, core or reamer bits can be used. The choice is determined by how much the hole needs to be enlarged. Reamers should be used when only a small increase is needed, while cores should be used when much more material must be removed.
A brad point or dowel bit is the same thing, and these are sometimes referred to as lip and spurs. They are often chosen for use on wood and plastic. They are cousins of the twist style, but can produce a neater hole. A twist bit can catch and pull fibers, leaving a messy hole.
Paddle or spade bits are often used with wood, although they can cause splintering when exiting. They are made almost entirely for hand drills. Woodworkers often prize them because they can produce a neater hole than most twist bits.
One type that is very popular with construction workers is the speed or step bit, also called a Unibit. These can drill holes in numerous sizes, eliminating the need to switch bits for each new task. They work with plywood, particle board, sheet rock, and many more materials.
Masonry bits are designed for use with an electric or battery powered hammer drill. Hammering of the masonry at the end of the bit helps increase penetration. They are marketed in a wide array of sizes as well as lengths.
Electricians have helped make installer bits popular. These may also be called bell hangers. The bit itself features a hole, and when the bit is inserted, it can fish wiring out from between walls and bring it back.
By selecting the proper type and size you need for the job to be performed, you can finish faster and with neater results. Most bits can be used with a portable electric drill, but there are times when you may have to resort to a hand bit. Fortunately, these times occur only rarely.