Types of Drill Bits
With a plethora of options available it can be difficult understanding which type of drill bit is best suited for your needs. Before purchasing a drill bit it is important to consider how often you plan to use it, what you plan to use it for, and the type of material it will be used on – this will ensure that you select the right choice for your projects every time. Here are some of the most commonly-used types of drill bits that you will find today.
Twist Drill Bits
Twist drill bits are one of the most widely used bits and can be used on a range of materials such as metal, plastic, wood, etc. Due to their multi-purpose applications and economic price, twist drill bits are a staple in many toolboxes and can be found in many styles and variations. They are best suited for drilling small holes, however they must be withdrawn regularly when drilling to remove waste material and prevent clogging.
Countersink drill bits produce conical holes that contain a smaller center hole that cuts through the material. This specialty drill is used often with wood and can be used to create countersink and counterbore holes to fit screw heads. These drill bits are best suited for soft materials such as woods and plastics; they would not work well with metals.
Masonry drill bits are best suited for hard materials such as concrete, brick, etc. Masonry bits usually operate using a hammer drill, breaking up the material while the rotating action expels debris through the flutes. Be careful to check that the bit is not over-worked as the bit can wear down after excessive hammering. It is also important to clean the bit in between drills to remove dust, and also to monitor usage to prevent overheating.
Auger bits work best for drilling large, deep holes in wood or materials of a similar nature. The screw tip first bores the hole and then pulls the bit through the material, creating a defined circular cut. It is typically designed with extra-large flutes that help remove the chips from the hole. In most instances an auger bit should be used with a hand brace; it’s not suitable for use in a power drill.
Flat Wood/ Spade/Paddle
As the name suggests, these bits are useful when boring large, flat-bottomed holes in wood, and should be used with a power drill. They contain a flat blade with a sharp tip in the center that marks the surface position and keeps the movement steady. Often flat wood bits contain two cutters at the edges of the blade to help create a cleaner cut. These bits often cause splintering, which can be remedied by completing the drilling from the opposite end of the hole.
Tile bits have a spear-like carbide tips that reduce cracks, making them ideal for drilling tiles and ceramics. While they can be used with a hand drill, they can also be used with power drills at slow speed. Note that when drilling glass it may be necessary to use a lubricant to ensure that the tip stays cool.
These drills are used to cut large, fixed-width diameter holes in wood or metal. The hole saw looks like an open cylinder that contains jagged edges around the circumference. Unlike most other drill bits that remove waste material from the interior of the hole, the hole saw removes material from the edge. It is typically used when installing hardware for doors or creating holes through which to pass wires.
The Forstner bit bores flat bottomed holes in wood. It is best used with a drill press in order to obtain better positioning and control of drilling movements. Be sure to remove the bit regularly to clean away dust material, as the bit contains no system for clearing chips from the hole.
Spur point / Dowel / Brad Point bit
These drills contain a central tip with two raised spurs that ensure they have a central point and two raised spurs that ensure that the drilling movements are straight. When used with a power drill, the bit cuts through wood quickly, creating clean and precise holes.