Drill Bit Buying Guide

HSS drill bits, also known as high speed style or twist drill bits, are the standard type of drill bits you’d expect to come across. They have spiral grooves twisting down the length of the body which remove debris, while the front edges cut into the material. HSS drill bits are used for drilling into wood, plastic, and soft metals because they’re resistant to heat so they won’t damage the material. 

Twist bits are hardwearing and can be sharpened if they become dull with a bench grinder or belt sander. They’re also more affordable than other types of drill bits. This, combined with their wide availability, versatility and variety of sizes makes them an ideal drill bit for DIYers and tradespeople alike.

You’ll find that HSS drill bits will need resharpening over time, and they’re often more fragile than many other drill bits. For this reason, they’re not suited for use on very hard materials, and may have a slower cutting speed than other drill bits. Twist bits may also drift along a surface if not used correctly, which could create uneven holes. 

Core drill bits have a hollow centre and diamond or carbide powder on the edge for extra cutting power. They’re used for cutting very precise holes of various sizes in materials including brick, stone and concrete. Core drill bits are most commonly used when holes are needed for large pipes or cables.

These drill bits are extremely strong and leave very clean holes in material. Core drill bits make relatively quick work of large-scale projects that would otherwise take a long time. Their long lifespan – as a result of the diamond or carbide tip – makes them cost effective.

Despite their cost effectiveness, core drill bits come at a higher upfront cost than other types – meaning they’re not suited to every budget. Core bits also require more skill to achieve clean, precise holes. You’ll also find core bits are bigger and bulkier than standard bits, so are less suited to tight spaces.

SDS drill bits have a slotted, cylindrical shank that fits into the chuck of an SDS drill and moves back and forth in a hammering motion when in use. They come in a variety of sizes and shapes, including fluted tips for hammer drilling and chisel attachments to remove material. SDS bits are made from durable materials such as carbide for added strength when drilling into masonry, concrete and other hard surfaces.

Due to the slotted design of SDS drill bits which holds them in place securely, they’re highly powerful – perfect for the most challenging of projects. They have a long life and are the only drill bits that can withstand the power of an SDS drill. 

SDS drill bits are typically more expensive than other types, such as standard twist drill bits. They’re also only suitable for use in an SDS drill, so they have limited uses. Because of the application they’re used in – such as masonry – a lot of dust and debris is created when using SDS drill bits.

Wood drill bits, also known as spade drill bits, have flat, paddle-shaped cutting edges and a centre point that can be used as a guide when drilling. They make round holes in wood for installing cables, pipes and conduit. Wood drill bits are made with high-speed steel or carbon steel and have different shank sizes for different drill chucks.

Spade drill bits are often less expensive than other drill bits designed for wood, and can bore holes at rapid speeds. Their speed makes wood drill bits ideal for large-scale projects. They’re also able to drill flat-bottomed holes for certain hinge types as well as complete holes in wood, meaning spade bits have more applications than you’d expect.

Holes created by spade bits can be rougher than other types of drill bits designed for wood, and may cause some splintering – choose an auger bit if you’re after precise, clean holes. They’re also less versatile than typical drill bits, as they’re only suited for drilling into wood. 

Masonry drill bits, as the name suggests, are used to drill into masonry such as brick, stone and concrete. They’re made of high quality hardened steel and often have a tungsten carbide tip to cut through hard surfaces. Masonry drill bits are available in a range of sizes and lengths to suit any project. 

The main advantage of masonry drill bits is that they make light work of cutting into very hard, dense materials that standard drill bits would struggle with. The tips of masonry drill bits are often shaped like an ‘S’, which helps to remove debris from the hole better than standard drill bits. 

Masonry drill bits are strong, just like SDS bits – but masonry bits have a straight shank so they are more likely to slip if they’re not secured properly. They’re best suited to powerful drills like percussion drills only, and won’t be much use in standard drill drivers. 

Multi-purpose drill bits are used in a variety of applications, including drilling into wood, metal, masonry and plastic. They’re often made of durable high speed steel and have a standard twist bit structure, a spiral flute to help clear debris, and a sharp point to guide the bit into the material. 

These drill bits allow DIYers and tradespeople alike to save time on large projects by not changing the drill bit between surfaces. Multi-purpose drill bits also allow you to save money and space by not having a wide range of drill bits filling up your toolkit. 

Whilst multi-purpose drill bits are great for a range of uses, they won’t perform as well as specialised bits. For example, wood drill bits will be best suited for wood, and masonry drill bits will best suit masonry. Multi-purpose drill bits are also less durable and accurate, especially when used on harder materials such as stone or brick.

Step drill bits, also known as unibits, are used for drilling progressively larger holes in sheet metal, plastic and other thin materials. They have a stepped design, with slightly larger diameters along the length of the bit which forms a cone shape. Step drill bits are commonly found in automotive or heating and venting applications.

Unibits can save time as you won’t need to change the drill bit when you need a slightly larger hole. They also create relatively clean holes in the material. Additionally, step drill bits are short, which can make it easy to move around at different angles.

These drill bits are not easy to resharpen because of their stepped structure, which could limit their lifespan. Step bits also have a higher price tag than multi-purpose drill bits or twist drill bits. They’ll also struggle to get through thick or hard materials.

Glass drill bits have a sharp, fine carbide tip to prevent glass from chipping or cracking when drilled into. They’re often used in precise glass-cutting applications, such as jewellery making. 

Drill bits made for glass are extremely precise and make clean holes. Tungsten carbide is stronger than steel, and the chemical makeup of the material makes glass drill bits extremely durable and long lasting. Glass drill bits are also sometimes suitable for drilling into tile, making them more versatile than you’d expect.

Glass drill bits are generally more expensive than standard drill bits – although for glass cutting, your options are limited as many other bits would crack the glass. They don’t have a wide range of uses, as they’re mainly used for glass and tile, meaning they’re not necessary for many DIYers.

Tile drill bits have a very strong diamond or carbide tip which are ultra-strong and therefore prevent the tiles from cracking or chipping. Most tile drill bits have a flat tip but you’ll also find spear point tips. Flat, diamond-tipped drill bits are perfect for porcelain and glass mosaic tiles, while spear point carbide bits work well for ceramic tiles. 

Tile drill bits can be used in wet conditions, which is ideal because lubrication – such as water – keeps the drill bit cool and are therefore more reliable when drilling. Tile bits make precise, clean holes due to the extra strong tip.

These drill bits can come at a higher price tag than standard drill bits, but if you want to drill into tile you won’t have any other options. If you’re looking to keep your toolkit small, tile drill bits have a limited use and may not be worth buying if you can avoid it.