Choosing a drill 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 over 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.
Most drills have two gears − the first gives less speed and more twisting force for screwdriving, and the second gear gives higher speed to drill harder materials.
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.
Cordless drills let you choose the level of twisting force (torque) for each gear, which is useful for screwdriving as it prevents overtightening 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.
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.
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.
The battery will run out if you don't drill often. A mains drill is a better choice if you drill rarely because some batteries stop working if not used.