Power tools make any task easier and faster. Popwer drills are the entry point for any DIY enthusiast.
If you are one of South Africa's many DIY enthusiasts, or even a professional contractor, an electric drill is probably the first power tool you will purchase and will be the most comon tool you will use. Modern electric drills have a variety of features and benefits, which can be confusing for anyone intending to buy one.
Corded or cordless
For an electric drill to function as a screwdriver it needs to have a variable-speed setting, torque control and a reverse drive. When using a drill as a screwdriver, a fairly low speed is necessary, so variable speed control is important.
The size of the screw, together with the type of material being drilled, will influence the torque required. Torque control ensures that screws are not driven in too far or too tightly. If you intend to use your drill as a screwdriver it should also have a reverse facility so that you can remove screws.
The ideal speed for a drill bit depends on its size and the material being drilled. Generally, larger bits need to turn slower than smaller bits to prevent them from overheating and losing their cutting edge. Drills with variable-speed control are therefore ideal. Some electric drills have an adjustable trigger stop, which can be set so that the drill is limited to a speed suitable for the job. A slow speed can enable a corded drill to be used as a screwdriver.
A hammer-action function allows the drill bit to ‘hammer’ its way into bricks and masonry. This type of action requires pressure to be applied by the user, which can lead to wear and tear on the bearings.
Chuck size and type
Chuck size determines the size of drill shafts that can be used. The common chuck sizes are 10mm and 13mm. 10mm chucks are suitable for most everyday tasks. Normally the larger the chuck size, the more powerful the motor. Traditional drill chucks needed a chuck key to open and close them. With a keyless chuck, these can be fi tted or removed with the flick of a wrist.
Most drills have a pistol grip with the speed-control trigger built into it. Heavier drills need an auxiliary, usually detachable, handle so that the drill can be held steady. Drills are mostly designed to be held in such a way that the user’s forearm is in line with the drill bit, allowing more pressure to be put behind the bit. Always pick up a drill and try it in your hands for comfort before buying. Check whether the trigger and other controls are easy to operate.