Everything You Need To Know About Drill Bits
Knowing what drill bit to use and when to use it means you’ll be well-equipped to tackle the project correctly the first time. However, this can be confusing because so many different drill bits are available. Understanding which drill bits are suited for which tasks will go a long way towards ensuring your project is successful.
This blog post will explain drill bit features, the different types of drill bits available, and when to use them.
Drill Bit Features
A drill bit might look like a simple tool, but much design and engineering goes into its construction.
To break it down into simple terms, let’s go over each part of a drill bit and what it does:
- Point: The pointed, cone-shaped end that cuts into the material. This drill bit section consists of a cutting lip and a spur.
- Spur: The spur is located in the centre of the point and helps the drill reach the correct position on the material.
- Cutting edge: The cutting edge scrapes away at the material in front of the drill. This feature generally varies from drill bit to drill bit.
- Flute: A flute or channel starts from the cutting lip and spirals down the body of the drill bit, ending with the shank. The flutes help the cutting lip discard the material being drilled.
- Shank: The straight portion of the drill bit that is usually clamped directly into a drill’s chuck.
Drill Bit Size
Drill bits come in many different shapes and sizes to suit different applications, with some better suited to cutting certain materials than others. Choosing a drill bit is important based on the size of the hole you wish to make and the materials you will be cutting through. The size of a drill bit significantly impacts the accuracy, depth, and shape of the hole your drill will make.
Most drill bits come with 3 standard measurements that you should consider:
- Diameter: the diameter of the tip of the drill bit or the size of the hole it will cut
- Total Length: the total length of the drill bit (including the shank)
- Working Length: the depth of the hole it is capable of drilling
Once you know what size of drill bit you’re looking for, you might want to consider the material and finish for your drill bit. Depending on the project, it can make a world of difference.
Drill Bit Materials & Finishes
| Drill Bit Material/Finish | Description | Best For |
| High-Speed Steel (HSS) | Durable, versatile, and commonly used for general-purpose drilling. | Wood, plastic, and softer metals. |
| Cobalt | Alloy with cobalt, offering superior heat resistance and durability. | Stainless steel, harder metals. |
| Carbide-Tipped | The Carbide tip provides extreme hardness and durability. | Masonry, tile, and abrasive materials. |
| Solid Carbide | Extremely hard, brittle, and ideal for industrial, high-speed applications. | Hardened steel, cast iron. |
| Black Oxide Finish | The coating improves corrosion resistance and heat dissipation. | Wood, metal, plastic. |
| Titanium Nitride (TiN) Coating | Gold-coloured coating for increased hardness and reduced heat buildup. | Various metals, extended lifespan. |
| Diamond-Tipped | Coated with diamond for precision and durability in very hard materials. | Glass, ceramics, stone. |
Drill Bit Types
N-Durance 25 Piece Ground Polished Twist Drill Bit Set
There are dozens of different types of drill bits for every application imaginable, so in this buying guide, we will cover only the most popular drill bits you might have a use for.
Twist Bit
Twist bits are the most common drill bits and are generally used for drilling into wood, plastic, and light metal.
Sealey AK3715W Brad Point Wood Drill Bit Set 15pc
Brad Point Bit
Brad-point bits are best suited for drilling into wood. The added point at the end helps ensure the bit stays in place while drilling and the extra-wide flutes help remove wood more efficiently.
Bahco BAH9629SET8 9629 Series Flat Bit Set 8 Piece
Flat/spade Drill bit
These drill bits are slightly uncommon but can drill large holes to adjust widths from ¾” to 3”.
Makita P-46464 5 Piece 200mm Performance Auger Drill Set
Augur Drill bits
Augur drill bits are primarily for wood boring and feature very large flutes to help remove more wood material.
Sealey AK3717TCM HSS/Masonry Drill Bit Set 17pc
Masonry Drill bits
Used with a hammer or rotary drill, masonry drill bits come in variable sizes and are used to drill into concrete or masonry.
BlueSpot Tools B/S20310 Countersink Bit Set 3 Piece
Countersink Drill bits
A Countersink drill bit, also known as a screw pilot bit, is a speciality drill bit used for drilling into wood. This bit can drill pilot, countersink, and counterbore holes in a single action.
Faithfull FAISDSET3 HSS Step Drill Bit Set of 3 4-30mm
Step Drill Bits
Step drill bits are intended primarily for drilling through thin metal but will also work with wood surfaces. The stepped design allows you to drill holes of different diameters with the same drill bit.
N-Durance M42 Bi-Metal Holesaw (16mm)
Hole Saws
Hole saws drill large holes through wooden and light metal surfaces to install door hardware or create an entrance for wiring. The cylindrical design also allows for easy disposal of the waste material.
FAQ
How can I sharpen a dull drill bit?
Drill bits can be sharpened using a drill bit sharpener or a grinding wheel. Regular sharpening can extend the bit’s lifespan and improve its cutting performance.
How should I store drill bits?
Store drill bits in a dry, organised container or case to prevent rust and damage. Keeping them neatly arranged by size and type will also make it easier to find the right bit for each project.
Why do my drill bits break or wear out quickly?
Improper speed, excessive force, or using the wrong bit for the material can cause breakage or quick wear. Ensure you’re using the appropriate bit and technique for the task.
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