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What is Drill Bit?

Whether you’re a qualified tradesperson or an experienced DIYer, your drill is probably one of the most used tools you own. But having a great drill is only half the story when it comes to getting a job done quickly and efficiently. Using the right drill bit for the task is vital too. But with so many drill bit types available, what should you choose?

This comprehensive drill bit guide will help you get kitted out for the job. It covers what drill bits are and what they’re made of. The types of drill bits available, what materials they’re best used for, specialist drill bits for specific jobs and the different types of shanks. You’ll also learn about drill bit angles and what size drill bit you need for various wall plugs and bolts.

You can view our range of drill bits here.

What is a Drill Bit?
A drill bit is a cutting tool that’s fitted into a power drill and used to cut holes in materials. They come in a wide variety of shapes and sizes, but they all have similar parts as follows:

Point: the top, cone-shaped part of the drill bit that consists of a spur and cutting lip.
Spur: this sits at the top centre of the point. It helps to get the drill bit into position.
Cutting lip: the part of the drill bit that cuts the material.
Flutes: a spiral channel that runs from the cutting lip to the shank. It helps to remove the material as it’s cut from the hole.
Shank: this part of the drill bit slots into the drill’s chuck. There are several shank types which we will cover later in this drill bit guide.
The part that differs between drill bit types is usually the cutting lip. Their different designs make some more suited to cutting through certain materials than others. There are also different designs depending on the power drill they need to fit, and the type of hole being drilled.

What Drill Bit to Use?

Before buying a drill bit, it’s important to consider what you need it for. You can purchase multi-purpose drill bits, but you’ll get better results by using one specifically designed for the material and type of hole being drilled.

A drill bit’s suitability for drilling into certain materials usually depends on what the drill bit is made from and coated with. The drill bit guide below describes the main options:

Drill bit materials:

High-speed steel: made from carbon steel with chromium and vanadium additives. It’s suitable for drilling wood, plastic and soft metals.
Cobalt: an incredibly strong alloy metal used to drill through tough materials. It can withstand heat and resistance and is the best drill bit for stainless steel.
Carbide-tipped: one of the hardest materials on the planet, this drill bit only uses carbide on the tip. It’s suitable for drilling masonry, tiles and concrete.
Solid carbide: a drill bit as described above, but it’s made entirely from carbide. It’s suitable for drilling into tough materials.
Tungsten carbide: made from a mix of tungsten metal and carbon. It’s even more hard-wearing than the standard carbide above. It is suitable for drilling into extremely tough materials such as masonry.

Drill bit coatings:

Black oxide: this coating helps drill bits retain lubricants and prevent rust from forming.
TiN: a titanium nitrate coating that slows down wear and tear on drill bits designed to cut metal.
TiAIM: a titanium aluminium nitrate coating that increases resistance to abrasion and heat on drill bits designed to cut metal.
SG: a silicone coating that helps a drill bit penetrate dense metals.

You may have also heard of HSS drill bits and SDS drill bits. So, let’s explain what they are:

A HSS drill bit is made from high-speed steel, as described in the materials section above. It’s often used in multi-purpose drill bits as it can be used on wood, plastic and metal. HSS drill bits are also the best drill bits for soft metals.

An SDS drill bit is a type of drill bit used in an SDS drill. SDS stands for slotted drive shaft, and it refers to how the drill bit is held in the drill’s chuck. The shank of the drill bit has double grooves, which keep it extra secure and facilitates outstanding hammer action. It’s made from tungsten carbide, and the drill and drill bit together make drilling holes into concrete, block and stone much easier.

High-speed Steel M35 Double Ended Drill Bit

HSS 6542 Double Ended Drill Bits Fully Ground

HSS M2 135° Double Ended Rivet Drill Bit

Gold Surface Treated Fractional Two Ended Drill Bit

135° Split Point Double End HSS Drill Bit Black Oxide 3/16″

Black Oxide Coated High Speed Steel Double Ended Drilling Bit 9/64″

Black Oxide Straight Shank Double Ended HSS Drill Bits