In this guide we’ll take a look at the best drill bit sets for the money.
I’ve compared build quality, variety of bits and cost
to give you my top recommendations.
What Is The Best Drill Bit Set?
More Detailed Drill Bit Set Reviews
This top quality drill and screwdriver metric accessory kit from Bosch provides you with a comprehensive set of nearly 40 drill bits, 24 short screwdriver bits, 10 long screwdriver bits, plus a set of sockets, a roller meter, a tape gauge and a magnetic holder, all neatly arranged in a rigid carrying case.
There are 5 drill and 3 titanium spade bits for wood, 11 HSS titanium nitride coated drill bits for metal and 6 carbide tipped bits for masonry. All the accessories can be used across with any brand of power tool.
A comprehensive selection of all the drill bits you will ever need for starting or enhancing your toolkit. Every bit is made from high quality titanium coated steel to lower friction and increase durability. The bits can be used for drilling wood, plastics, metals and steel and they range in diameter from 1.5 mm to 10 mm, with more at the lower end to cover you in the case of breakage.
The bits are arranged in compartments for easy selection in a well-made solid metal case, and the set represents great value for money.
This high quality power drill set from Makita covers pretty much every accessory you’ll need to accompany your collection of power tools. Firstly you get a selection of standard drill bits for negotiating wood, masonry, metal and PVC, including 6 HSS drill bits, 6 Masonry bits, 6 Brad point bits, 3 flat bits, 4 drill stoppers and 4 holesaws. Also included are 30 screwdriver bits, 13 nutdrivers and a hex key. Finally the kit comes with several accessories including a drill gauge, an arbor adaptor, a bit driver, a centre punch and a counter sink. In other word pretty much every accessory you’ll likely need to get you up and running!
What is a Drill Bit Made of?
A key feature of drill bits is the material they are made of and therefore their relative strength and suitability for drilling into different densities of material.
In a nutshell bits made from the softest metal are only suitable for drilling the softest materials.
A soft metal bit would fail when drilling anything other than a soft wood but a hard bit would make short work of that same job.
The softest bits are therefore the least versatile but also the least expensive.
Most drill bits are made from forms of steel or cobalt. They can have modified tips to make them more resilient and be coated with compounds to reduce friction and heat.
If we traverse the soft to hard scale, steel and carbon steel bits are the best choices for general woodwork.
High Speed Steel (HSS) bits can handle soft woods, hard woods, most plastics and many metals. This is the most versatile and reasonably priced general purpose bit.
Then come carbide tipped drills which can for instance drill into screws. They can handle heat better than HSS bits.
Next up are cobalt drills which can drill into stainless steel, other thicker metals or even other drill bits (usually when those bits are broken and need removing)!
Finally come carbide bits with a coating of diamond grit used for drilling the hardest metals and TCT (Tungsten Carbide Tipped) and diamond core bits. These are used for drilling into the hardest rock and stone.
Drill Bit Coatings
Most drill bits are coated with a chemical compound. The most basic is black oxide, used for protection against oxidation and rust.
Then comes Titanium Nitride (TiN), recognised by its gold colour.
Titanium Aluminium Nitride (TiAlN) is the most effective and can extend the life of the drill bit several times over.
For serious drilling into hard materials heat build-up from the friction will be significant. You will need to douse the hole with water if drilling into ceramics, concrete or stone or with a special lubricant if you are drilling into metal.
For general purpose drilling though Titanium coated HSS bits would be a good practical and not overly expensive choice.
Base Of The Drill Bit
The base of the drill bit (shank) fits into the chuck. Not all shanks fit all chucks.
Most drills and drill drivers have 3 jawed chucks and they accept both round and hexagonal-shanked bits and accessories. That is good because there are many choices out there.
However Cordless Screwdrivers and Impact Drivers only accept bits with hex shanks.
Also SDS+ Rotary Hammer Drills and SDS Max Rotary Hammer Drills take SDS slotted-shanked bits.
Top of the Drill Bit
No matter the shape of the lower shank, the upper section of the drill bit consists of a flute or spiral groove with a sharp point at its tip.
The tip centres the bit while it is spinning. The cutting is done by the sharp upper edge of the spiral groove.
The waste material gathers in the groove itself and works its way back up the drill as it spins. Waste from softer woods for instance may clog the groove so in this case you will have to stop drilling and clean it out periodically.
Different Kinds of Drill Bits
The twist bit is your go to bit for drilling into wood, plastic and metal. It has a point at its tip and a round shank.
A typical set of twist bits comprises a range of diameters from a small fraction of an inch to usually 9 mm (⅜”). This largest ⅜” bit in the set aligns with the ubiquitous ⅜” chuck found on many general purpose drills and drill drivers.
Larger shank diameters are available (for fitting in larger capacity chucks) but they tend to be sold as individual items and are proportionately more expensive.
Bits with tapered shanks are also available so a smaller maximum chuck size (e.g. ⅜”) need not be a limitation when drilling a larger (e.g. 13 mm or ½”) hole.
Similarly you can purchase longer than standard length versions of the twist bit for specialist applications, and it goes without saying that you must do this as opposed to not seating the base of a standard length bit as far into the chuck as it will go.
Smaller diameter bits are relatively brittle (no matter what coating is applied) and will fracture easily if you don’t secure them in the chuck centrally or apply pressure directly and evenly when drilling.
The masonry bit is instantly identified by its 2-winged blunted tip. As its name suggests it should be used whenever you need to drill into brick, light concrete or stone. At the same time your hammer drill or hammer drill driver needs to be set to hammer mode for this.
The masonry bit is able to accommodate the force and percussion generated by the hammer action because it is constructed of a tip made of extra resilient tungsten carbide that is bonded onto a steel shaft. More expensive types have the tungsten carbide tip replaced with a silicon alloy called durium.
When you are placing fixings into a hole drilled into brick, light concrete or stone don’t forget to insert a wall plug or equivalent into the hole first so the fixing has something to bite on, otherwise the fixing will not be ‘fixed’!
Before drilling match the fixing size to the plug size and then the plug size to the hole size. Usually the fixing and plug come together and fit snugly together. The plug and the hole need to be snug. Usually the diameter of the plug is 1 mm smaller than the hole.
A set of masonry bits will typically range in diameter from 3 to 13 mm.
If you’re a general DIYer then a set of HSS twist bits and masonry bits should be all you’ll need.
Sure the bits will eventually wear out or you might break one or two of the smaller ones and have to replace them but most eventualities should be covered.
If however you’re considering more specialist projects read on because there are plenty more options available to you.
There are a few different kinds of woodworking bits and these are described below.
- Brad Point Bit / Dowel Bit / Lip and Spur Bit / Wood Bit
This bit is known by a few different names.
If you want to drill into soft or hard wood more accurately and cleanly than with a twist bit but don’t need a hole too large in diameter then a Brad Point bit is best.
This bit has a very sharp carbide tip (called the ‘brad’), 2 sharp spurs on the top edge which score the wood and sharp top edges of the flute which all combine to cut the hole to very clean finish.
One very common use for the Brad Point bit is to create holes for dowels, so much so that it is often referred to as a ‘dowel bit’.
Diameters typically range from 3 to 13 mm but can go much larger.
If however you need larger holes you have a choice, based on how clean a finish you want to your hole.
Spade Bit / Flat Bit
If your work is more construction based and you want to drill large holes into lumber, drywall or floors and without too much concern for the look of the hole, then go for the Spade bit (aka Flat or Paddle bit).
These are large inexpensive bits but what you save in dollars you sacrifice in the finished product. The rough finish is down to the fact that the bit does not have any flutes, it’s just the edges of the spade that do the cutting.
Therefore it’s almost certain you’ll see some splintering at the exit of the hole, although this can be reduced if you clamp some waste wood to the back of the piece being worked on.
Also because there are no flutes you will have to pump the drill back and forwards to remove the sawdust that accumulates.
In general the Spade bit is quite large ranging from 6 mm to 38 mm in diameter and can go to over 30 mm in length.
There are a few variations of the Spade bit.
Some have slightly raised spurs at the left and right corner of the spade to give a slightly cleaner finish and reduce splintering.
Others have a threaded rather than flat point that help draw the drill into the hole.
You can also get spade bits with a hole near the top into which you can insert a cable for dragging through the hole as you drill through walls or floors etc.
Auger bits are a step up from Spade bits – well they have a flute for a start!
They are also designed to drill deep holes into wood, but this time with a smooth finish, not just on the sides, but with a cleanly cut base to the hole too.
The top edge of the flute comes to a sharp point beyond the centre tip of the drill and it is this that gives the clean finish.
The presence of the flute means most of the sawdust gets removed as part of the natural drilling action (unlike the Spade bit).
The centre point is threaded, so the rotation of the bit naturally draws the drill more towards the hole.
You can find Auger bits with diameters ranging from 6 mm to 36 mm and lengths to 450 mm!
Forstner bits are the most sophisticated of the larger drill bits used for drilling wood and they cut the cleanest holes, both in terms of inner circumference and the base of the hole.
This is achieved by a cleverly engineered design consisting of vertical circular cutting lips and horizontal cutting blades.
However this arrangement sacrifices a central tip, which means you have to take more care in aligning the bit. A drill press is often suggested to overcome this.
The Forstner bit also lacks a recognised flute so there is less cutting edge over the length of the bit and therefore you have to exert more pressure than with other drill bits to achieve your desired result.
If you require a high level of precision in your woodworking projects you should choose this type of bit, even though it is the most expensive category of wood drilling bit.
Shank sizes often range from 6 mm to 10 mm but the diameter of the cutting edge itself can go to 72 mm.
This interesting accessory replaces the need to purchase several individual bits with one bit.
The tip is comprised of both a fixed and adjustable cutter that work in conjunction with each other, and a threaded centre point that draws the bit into the hole.
This was a common item years ago when drill bits were relatively expensive. That is not the case these days and although the bit is quite versatile it is also quite cumbersome.
It may still be quite handy to keep in your toolkit but more to be used as backup when nothing else will do the job.
These are used to form an indented cone at the top of a hole so the top of a countersunk screw can lay flush with the surface of wooden or plastic material.
Bits for Drilling Metals
If you are drilling metal and need a more precise finish than your twist bit can give you, consider a Step drill bit.
This is an unusual looking accessory and quite expensive, but it enables you to select different hole sizes for drilling without needing to swap out the bit.
Its conical profile is made up of a series of ever increasing ‘step’ sizes, whose diameters range from maybe 6 mm at the top of the cone to 36 mm.
You drill down to the diameter of the hole you need and continue drilling up to the depth of that step.
The bit’s limitation though is that the depth of hole you need to drill cannot be larger than the depth of the step, which is typically 3 mm.
So the most suitable application for this bit would be for drilling sheet metal.
A vertical flute runs through the centre of the bit and opens to the outside to allow for the removal of burr and swarf.
Bits for Drilling Other Hard Materials
There are 2 scenarios for drilling into hard materials…
the precision hobbyist type of work where you’re drilling small holes into materials like ceramics, glass and stone and a neat finish is paramount
the heavy duty DIY / construction / project type work where you’d typically be drilling into masonry, concrete or stone, and a precise finish is less important
Diamond Tipped Bits for Hobby Work
For hobby work drill bit shanks range from a tiny 1 mm to 3 mm and the tips can come in various shapes, all encrusted with a layer of diamond grit.
Be aware that if you don’t accurately judge the hardness of the material being drilled and the pressure applied to the drill, the bits will regularly fail, due to their thin and brittle nature.
That is why they are commonly supplied in large sets.
Now we come on to DIY projects where you want something more specialised than a standard masonry bit for drilling hard material.
The specialised tile bit consists of a pointed tungsten carbide tip welded onto a steel shank.
However by far and away the solution for drilling into hard materials is provided by hole saws.
Are hole saws actually saws or bits? Probably a bit of both!
A circular cut is made into the material leaving a core or plug that requires levering out with a screwdriver or chisel.
The cut is made either by the impact / percussion action of a TCT (Tungsten Carbide Tipped) bit (usually in a Rotary Hammer Drill) or the grinding action of a diamond coated bit (of which there are 2 types – the bonded (aka electroplated) diamond bit and the sintered diamond bit – these are described in detail later.
Before we discuss the differences between these hole saws / bits it is worth pointing out that working with any of them in concrete or stone (i.e. their most common applications) creates much friction and therefore heat build-up, potentially causing damage to the drill bit and, worse, injury to yourself.
You should take obvious measures to avoid this, such as drilling slowly and not applying much pressure to the drill (i.e. ‘let the drill drill’), but to avoid this even more you should flush cold water around the bit and hole.
There are a number of ways to do this, depending on whether you are drilling horizontally or vertically for instance, or whether you have a buddy around to direct a hose pipe, or the job is small enough to immerse the material into a container of water.
Any which way all 3 bit types are designed to work with a lubricant and they all contain holes to allow it to pass through. When you are up and running with the drilling and have water flowing, pump the drill up and down now and again to regulate the heat versus coolant dynamic.
You should also use a hole saw with a drill that has a clutch, so if the drill gets stuck for any reason you can quickly disengage the drive and prevent damage or injury.
And don’t forget to take extra safety precautions when drilling into hard material. The most obvious general safety measures are segregating the water and electricity supply lines and wearing safety goggles.
So now let’s look at these 3 types of bit in more detail.
Bonded Diamond Drill Bit
The bonded (electroplated) diamond drill bit is the least robust of these 3 hole saws.
It is typically designed to grind (not cut!) holes of up to 50 mm in diameter with a high level of accuracy in all but the hardest of materials.
Glass, ceramics and light stone are typical uses.
You should certainly avoid using this bit with concrete and hard stone though.
It consists of a round shaft welded to a steel cylinder. The outside top rim is encrusted with a band of diamond grit chemically bonded to the surface.
Go carefully with this type of bit though. It works by grinding rather than cutting so applying too much drill speed or pressure in too hard a material will cause the diamond grit to break off.
This will compromise the drilling process itself but also make the drill more difficult to balance and centre.
This bit is the business for fine work in any material classed as ‘reasonably hard’.
It will however struggle and degrade if misused.
For heavy duty drilling into the hardest materials though consider one of the following 2 options.
TCT Core Drill Bit
The TCT (Tungsten Carbide Tipped) core drill bit is more robust than a diamond bonded bit but it gives a less accurate finish.
It consists of a steel cylinder up to 6” in depth with several Tungsten Carbide flat teeth welded to its top rim to form a cutting edge.
The cylinder usually includes a detachable pilot bit that extends out from its centre, since hole saws can be awkward to align.
Once the beginnings of the hole are formed the pilot bit can be removed.
The shaft of the TCT bit is welded to the steel cylinder and slotted so as to fit into the chuck of a rotary hammer (SDS) drill.
The base of the TCT bit’s cylinder can also be threaded to accommodate an arbor which in turn slots into the chuck of an SDS drill.
The rim of the arbor though can be a limiting factor in the depth you can drill so the welded shaft resolves that problem.
TCT bits are meant to be used with a hammer action.
An SDS drill is important because any heavy action with a ‘non’ SDS drill into hard material would likely cause the shaft of the bit to slip in the chuck when operating in hammer mode.
The slotted SDS chuck and bit assembly make this impossible.
Also most SDS drills have a clutch, which again is important.
If the drill snags for any reason you need to disengage its rotation as soon as possible, otherwise injury could result from drilling in such hard material!
Sintered Diamond Drill Bit
Sintered diamond drill bits are the most resilient of all hole saws.
Like bonded diamond bits they grind rather than cut (TCT core bits cut).
Sintered diamond bits have a steel cylinder, but unlike bonded bits with the outside top rim of the cylinder coated with a layer of diamond grit, sintered bits have a thicker steel cylinder core with the top rim composed of several flat teeth impregnated (not just coated) with diamond grit.
This means that should grit on the surface of the teeth dislodge through the grinding action then more grit will manifest itself from underneath.
Sintered bits therefore last many times longer than bonded bits but they are that much more expensive.
Like TCT core bits larger diameter versions can also have a removable carbide tipped pilot bit extending out from their centre to help with alignment.
A sintered diamond core bit can be used with a regular drill but not with hammer action.
The ‘grinding’ should be at low speed (and therefore higher torque).
Low speeds may mean longer drilling time but you will achieve a neat finish and prolong the life of the diamond bit.
Since sintered diamond drill bits are expensive they tend to be sold individually.