A Guide to Drill Bits: Types of Drill Bits Based on Material, Shape and Purpose

Using the right drill bits for the job can go a long way in ensuring the things you want to fixate stay secure for a long time. But with so many drill bits available, how do you know which ones are the right ones for your project? Understanding the differences between the types of drill bits can go a long way in making your work more secure and more efficient. In order to do so, it’s best you go back go the very basics, and learn everything there is to about drill bits.

What Are Drill Bits and What Are They Used For?

Drill bits are rotary cutting tool accessories used to make holes. Their purpose is to contact they’re material they’re drilled into with the pointy end, while the back end is clamped in place by the jaws of the drill chucks. There are quite a few types and styles of drill bits, all of which serve a different purpose. In this article, I’ll focus on those mainly used in DIY projects.

You’ll find masonry drill bits for sale, as well as drill bits used for drywall, wood and metal. Using drills bits suitable for the material they’re intended for will make sure you get long-lasting fixtures that don’t damage the material. Let’s elaborate on that.

Drill Bits Based on Working Material

Masonry Drill Bits

Masonry drill bits are intended for surfaces like brick, mortar and concrete. When shopping for masonry drill bits for sale, you’ll probably notice that they feature twist bits with a carbide fin at the point. The fin breaks through masonry, whereas the flutes on the bits’ body removes the excess material. Masonry bits are commonly used with hammer drills, which is a specialised tool adding rapid hammering action to the bit. As a result, you can reach fresh masonry and remove dust faster.

Metal Drill Bits

If you need to drill into materials like stainless steel, you’ll need an HSS (high speed steel) bit. These bits are resistant to high temperatures which are generated when drilling into metal materials. Moreover, the flutes on the twist bit throw off metal strands. However, if you’re working on thin materials or you want to widen existing holes, you’ll need step bits to get the right sized hole. For making holes in 2-3cm thick metals, consider hole saws.

Wood Drill Bits

The most commonly used bits for drilling into wood are twist drill bits. These feature a brad point that helps create a bit of “bite”, and prevents the bit from going across the surface as you start drilling harder. For holes of 2-3cm, or larger, consider spade bits.

Drill Bits Based on Bit Material

High-Carbon Steel

One of the most robust materials for bits, suitable for drilling into plastic, metal and wood. They have one downside, though – when drilled at higher speeds, they can overheat, and as a result, soften and become dull. This generally happens when drilling metal.

High-Speed Steel

These bits can be used for prolonged drilling. They are quite similar to high-carbon steel bits when drilling wood, drywall or plastic, except they’re better for drilling into metal. If you’re contemplating whether you should get a high-carbon or high-speed steel bit, and money isn’t a concern, always opt for high-speed steel bits.

Carbide

These drill bits are much more durable than the aforementioned two, but they’re also considerably more expensive. Most DIY-ers don’t require that type of performance, but if you think your project is in some need of true resilience, then you should definitely consider them. These bits sharpen quite well, so even if they get dull, you don’t have to throw them away.

Drill Bits Based on Shape

Twist Bits

These bits are the most common shape of drill bits by a large margin, simply because they’re suitable for the widest range of applications. They get their name from their spiraled grooves, which are also known as flutes. As the bit bites into the material, the flutes remove the material out of the hole. Many bits, including masonry and brad bits, are simply variation of basic twist bits.

Spade Bits

These bits are flat, feature a sharp point in the centre, and material flaring out to either side. They remove a large portion of the material. The sharp point prevents the bit from sliding across the surface, while the tips of the material flaring score the outside perimetre. Lastly, the spade blades chip away material. These bits are mostly used for drilling wood.

Step Bits

These bits are extremely versatile. Rather than having a cylindrical shape, they feature a cone-shape and a distinctive stair-step profile. Every step is one drill size bigger than the next. This allows you to drill holes just the right size, or drill multiple holes of various sizes without changing the bit.

Hole Saws

These bits also remove a lot of material, but rather than chipping the material out, they cut the outside diameter of the hole. As a result, you get a round disc of core of material.