Guide to drill bits

October 16, 2018

The common types of drill bit, what we recommend & how to fit a drill bit into a rotary hand drill.

close up of ten universal drill bits
Author: Muddy Faces

Age Range: 3+

Duration: less than an hour

Location: anywhere

Time Of Day: any time

Season: any

Tags: drill, drill bit, guide, hand drill, tools

Category: tool use & traditional crafts

What is a drill bit?

A drill bit is a metal cutting tool that fits into a drill (drilling machine) to make a cylindrical hole. Drill bits come in many shapes, sizes and with different coatings. Some bits are manufactured specifically for wood, metal or masonry and some are for universal use.
Most bits have a circular cross section, but some have a non-circular cross section, like the auger bit (see below).

Which bit to use?

When working with hand tools with groups, we often recommend a HSS universal drill bit rather than a wood (lip and spur) drill bit.

The lip and spur drill bit has a very effective cutting action which is good for drilling wood with an electric hand drill, or for a very competent hand drill user. The lip and spur drill bit needs to turn at speed – if not it is likely to cut into the wood and jam. Once it is jammed it can be difficult to release it from the wood.

The HSS/general bit does not have such an effective cut – it has more of an attrition action, which means you need to drill for longer, but it is more tolerant of slower and variable drilling and is a lot less likely to dig in when working with slower hand tools.

pole clamped to a log plank being drilled by a person using a rotary hand drill

Wood bit

Wood bits tend to have a sharp point at the end (the point is sometimes referred to as a brad point or lip and spur). The point helps to keep the bit in position when starting off drilling.

one wooden drill bit

Metal bit

A metal bit has a shallow point at the end. It is usually manufactured with stronger steel and coatings. A metal bit can be used to drill wood.

one universal drill bit

Universal bit

A universal bit has a shallow point at the end and is a general-purpose bit that can be used in a variety of materials including wood.

10 stubby drill bits universal

Auger bit

An auger bit is commonly used in a brace hand drill (Carpenter’s brace) and usually has a non-circular cross section at the base. An auger bit has a deeper spiral flute which is more effective at chip removal. They tend to come in larger sizes for drilling wider and deeper holes.

auger bit