Best electric and cordless drill brands
How to buy the best drill
Article 3 of 3
How to buy the best drill
We explain the key features of electric and cordless drills, to help you work out how to choose the best drill for you.
Though drills are primarily designed to drill holes, many have lots of extra functions such as hammer action, variable speeds and gears, that enable you to do much more.
There's a huge range to choose from - priced from less than £50 to more than £350 - so it's helpful to work out what you want to use it for before parting with your cash.
Read on to understand what the different features available are, and watch our DIY expert video as he explains what they're useful for.
Once you've decided what type to go for, head to our best and worst drill brands page to find out which are the top rated brands for reliability, build quality and value for money.
Choosing a drill
For basic tasks, a cordless power drill with a rechargeable battery may be the best for you. They lack the power of mains-operated drills, but they're lightweight, easy to handle and can be used almost anywhere.
However, if you're taking on tougher tasks, or plan to use the drill a lot, then you might prefer the extra power and torque (twisting force) of a corded electric drill.
Types of drill
Drill drivers offer rotary drilling and screwdriving, but there's no hammer drilling. Cordless drill drivers can be used for high-speed rotary drilling for most jobs around the home, such as drilling in wood, interior walls and metal.
Combination drills combine high-speed rotary drilling, screwdriving and hammer drilling. It’s the hammer drilling that helps to set combination drills apart from other drills and drill drivers. It also means they can be put to work on very hard surfaces that rotary drills can’t handle. You'll need a combination drill if you intend to drill through concrete.
Hammer mode: This lets you drill into hard materials such as concrete. Rotary drilling is supplemented by a hammer action, which allows the drill bit to strike the surface thousands of times a minute and puncture extremely hard and dense surfaces. Use tungsten carbide-tipped drill bits when hammer drilling.
Rotary drilling mode: Rotary drills are ideal for basic DIY tasks, such as drilling holes to hang pictures. They rely on fast rotation (around 3,000rpm) so are best for small holes or on softer materials such as wood, metal or plastic, so you won't need to use hammer mode.
Screwdriver mode: Hammer drills also come with a low-speed screwdriver mode. This provides lower speeds, with more twisting force.
Percussion drills rotate at around 3,000 revs per minute (rpm), but for more power their hammer action pounds the turning drill bit at around 40,000 blows a minute.
Simple DIY jobs, and softer stone such as limestone or light concrete, are no problem. Hard stone, such as granite, produces strong vibration and noise because you need to push harder to activate the hammer action. Most percussion drills have one gear but two gears give better screwdriving control.
When we tested cordless drills we challenged each to drill into metal, concrete, sandstone and wood. You can find out more about how we tested cordless drills, and see which earned our recommendation.
Key drill features
SDS and normal drill bits
Most hammer drills need special ridged 'SDS' drill bits. These fit into grooves in the drill's chuck (rotating part), allowing the bit to be propelled forward.
To drill without hammer action ? for small holes in metal, say ? you need a normal bit. Some drills have a separate chuck for this. But, for most drills, you screw an adaptor to the SDS chuck, which is awkward and makes the drill top-heavy and harder to control.
Drill size and weight
Size and weight can vary greatly. Some of the bigger hammer drills weigh more than 5kg ? most people will find this far too heavy for sustained drilling. Also consider size ? small drills will be more comfortable and easier to use in small spaces than some of the more macho models.
The chuck is the section that holds the drill bit (the metal shaft that makes your hole). Modern drills have keyless chucks, so gone are the days of cursing the eternally lost key when you want to change the bit. Most models can take bits with diameters of about 0.5mm to 10mm or 13mm.
Look for a drill with more than one gear. Most modern drills have two gears. The first gear gives low speeds and higher twisting force for screwdriving, the second gives higher speeds for rotary drilling. If a drill only has one gear, it’s unlikely to be able to be successful at both drilling and screwdriving.
Cordless drills come with variable torque settings, so you choose the level of twisting force for each gear, which is useful for screwdriving as it prevents over-tightening or screw damage. Few mains drills let you do this.
Use higher torque for larger screws – if you're unsure which you need, start low and then increase it. The number of settings ranges from six to 31. You're unlikely to need 31, but it's helpful to have lots of choice.
Get the torque setting right, and the clutch will disengage the drill motor when the screw is flush with the surface being screwed into. The torque setting you need will depend on how hard the surface you’re driving screws into is.
Drills with a T-shaped handle centre their weight so they feel more balanced. It's worth visiting a DIY shop to compare the feel of models you're considering. A screw-in second handle can be really useful to balance the weight and give you better control of the drill.
If you're buying a cordless drill, you'll need to consider voltage. Generally, the higher the voltage, the faster you finish the job, and the longer the drill runs without overheating or needing recharging.
But the drill needs to convert the power efficiently. Still, an 18V or higher drill is best for tougher drilling, which quickly drains a smaller battery.
Nowadays, most drills recharge in about an hour or less. But some can take up to five hours. Luckily, plenty of drills come with a second battery pack so one recharges while you use the other.
In our tests, we found that the very best drills we tested can drill more than 100 holes in sandstone on a single charge. The worst can manage only around 30.
A mains drill is a better choice if you drill rarely because some batteries stop working if not used.
It’s a good idea to buy a cordless drill that comes with two batteries. If the drill you’re looking to buy only comes with one, consider buying a spare. If your second battery is charging while you’re drilling, you won’t have to stop work if your battery runs out of charge mid-job.
Lithium-ion (Li-ion) batteries are becoming more common and provide the best energy storage available for cordless drills. Nickel Cadmium (NiCd) batteries don’t offer the energy storage capacity of Li-ion.