Electric Drills and Screwdrivers Buyers Guide

The electric drill is easily the most common power tool in use today - there are few DIY jobs around the home that won't require one sooner or later.

Advances in rechargeable battery technology have seen the rise of the cordless drill and the cordless screwdriver, both of which offer convenience and ease of use away from the mains. A cordless drill still doesn't have the power of the mains version, but could be all you need if you're not a heavy user. Check out our guide to help you decide which type to choose. Any difficult terms are explained in our jargon buster.

The types of drill and cordless screwdriver on the market include:

- Mains-powered, single or multi-speed drills that may have features such as hammer action, reversing, keyless chucks and torque control.
- Cordless drills, with some or all of the above features and a variety of battery power outputs. Batteries are usually removable and replaceable.
- Cordless screwdrivers, with features such as spindle locks, torque control and variable position handles. Batteries are usually built in.

When buying a mains drill you should consider:
Motor size (in Watts) - will it be powerful enough for your purpose?
Chuck size - a bigger chuck will hold bigger drill bits.
What functions you need - drilling into masonry is difficult without hammer action, for example.

When buying a cordless drill, think about:
- Battery power - more volts means more performance and more time between charges
- Recharging time - do you need quick top-ups or can you leave the tool overnight?
- Are additional features that add to the price worth it?
- As with a mains drill, what functions you need - drilling into masonry is difficult without hammer action, for example.

Screwdriver points to consider include:
- Battery power - more volts means more performance and more time between charges.
- Can it be fitted with a chuck for light drilling?
- Recharging time.

Cordless drills have grown steadily more powerful in recent years. They can now tackle more jobs around the home and garden, while the lack of a mains cable makes cordless drills safer and more convenient.
However, cordless drills still don't have the sustained drilling power of the cheapest mains-powered drill, especially in tough materials such as steel or masonry. They have smaller chucks, so can only drill correspondingly smaller holes. Their maximum speed (rpm) is also much slower, so they're not very effective with accessories such as sanding or grinding attachments. Batteries run out, so unless you have two batteries with one permanently on standby, there may be times when you can't use a cordless drill. Cost is also a factor as cordless drills are far more expensive than mains versions.

We have looked at power, speed, hammer action, reverse, chucks, torque control, gears and accessories for both mains and cordless drills. Either read all our tips or jump straight to the section you want by clicking on the appropriate sections beside.

Mains drills
Mains drills are rated in Watts, the higher the rating, the bigger the motor and the more power available. Drills aimed at home users start at around 400W; 550W is more than enough for most users, while higher rated units - 650W to 1,000W - will suit the serious do-it-yourselfer and some professional users.

Cordless drills
The size of the battery (in Volts) determines the amount of power available on a cordless drill. Batteries can be recharged many times - they'll last for years in normal use. Cordless screwdrivers are usually supplied with a wall-mounted charging unit which trickle-charges the tool while it's stored. A full recharge could take anything up to seven or eight hours.
Cordless drill batteries recharge faster, depending on the type of charger supplied - anything from 15 minutes to five hours, though three-hour chargers are most common. The fast-chargers could easily cost more than the drill and are aimed at the trade, where lack of a battery could slow down a job. A second battery, coupled with a one-hour charger, is probably a better buy if you envisage using a cordless tool for long periods.

Mains drills
Few mains drills today are single or two-speed only. Most offer variable speeds up to 2,700-3,000rpm which allows for more efficient drilling (slower speeds for bigger holes, for example) and greater control, as you can start slow and build up speed by simply squeezing the trigger. Many variable-speed drills have a switch which allows the maximum speed to be pre-set, preventing you going too fast in delicate materials, for example. Single speed drills run fast - around 2500rpm - and can be more difficult to control in some materials or with larger drill bits.

Cordless drills
Cordless drills generally have much lower speeds than mains drills - commonly a maximum of around 650-800rpm. However, the latest high-powered drills with 18V batteries have maximum speeds of 1600rpm making them viable for use with some accessories. Variable speed is virtually standard; a few have two speeds.

Mains drills
Most mains drills have hammer action, a feature used when drilling into masonry (with special masonry bits) that allows the chuck to move in and out as it rotates. This 'hammers' the material being drilled, breaking it up as the drill rotates and making drilling easier and quicker.

Cordless drills
Hammer action is only found on more powerful cordless drills as it places a heavy drain on batteries. Useful for occasional use in relatively soft masonry, but a mains hammer drill is usually more effective.

A common feature on mains units and standard on cordless drills. It allows a drill that has jammed in a hole to be 'wound out' by reversing the direction of rotation. On a variable-speed drill it means the drill can be used for removing screws.

Drill chucks are three-jawed gripping devices that can be adjusted to hold bits and accessories of different diameters. Two sizes are common; 10mm and 13mm - the measurement refers to the maximum diameter of drill that each will hold. 10mm chucks are standard on cordless drills and are only found on low-powered, single speed drills. Keyless chucks dispense with the traditional toothed key that's required to tighten the chuck around a drill or accessory. Instead the mechanism can be easily adjusted by hand. They're almost universal on cordless drills and are becoming more common on mains units.

Torque control allows the user to pre-set the force at which the drill stops turning. Mostly used when screwdriving, as it prevents a screw being driven too far into the material. The feature is common on cordless drills, less so on mains units, and then only on units with variable speed.

A few of the bigger cordless and mains drills have two mechanical gears fitted. By shifting to the lower gear, the full power of the drill can still be used without the rpm dropping too much - just like a car driving up a steep hill. The lower gear gives more control when drilling large-diameter holes or holes in tough materials, when it can help to prevent the drill stalling and damaging the motor.

Mains drills
Nearly all mains drills will come with a removable front handle, which gives a better grip on the tool and a depth stop. This clamps into the front handle and allows drilling to a pre-set depth. The front handle sometimes doubles as a drill bit store. Variable speed drills may be supplied with a double ended screwdriver bit.

Cordless drills
Cordless drills are supplied with a charger and a screwdriver bit, which is stored in a magnetic or push-fit recess on the drill body. Many units come with a carry case for the drill and charger.
There are often special packs on offer at Christmas, for instance, perhaps combining a mains drill and power screwdriver or adding drill bits or sanding accessories. These can represent good value, but be sure to look carefully at the specifications of the tools - a carry case may not be as much use as a more powerful motor or battery.

Look at our points on power, spindle locks, torque control, detachable chucks, adjustable handles and accessories for electric screwdrivers.

Power
2.4V or 3.6V is the norm here; the latter will drive or remove more screws per charge and have more power for tough tasks.

Spindle lock
Automatically prevents the spindle turning when the motor stops turning, allowing the unit to be used as a manual screwdriver. Very useful for that final twist of a tight screw or when removing a stubborn fixing.

Torque control
Cuts out the turning force at a pre-set level to prevent screws being driven in too far.

Detachable chuck
A few screwdrivers come with a 10mm chuck that slots in the bit holder and can be used for drilling small holes.

Adjustable handle
A feature that allows part of the handle to twist to give a pistol-type grip like a drill. It may be more comfortable for some users when applying pressure on stubborn screws, but is of little real benefit.

Accessories
Rechargeable screwdrivers will come with one or more screwdriver bits, a charger and occasionally a chuck or carry case.

Mains drills
- A single-speed mains drill with hammer action and reverse functions could cost as little as £15.
- A mid-range 500W variable speed unit with hammer and reverse should be around £35-40.
- Around £100 will buy you a 1,000W powerhouse with keyless chuck and all the above functions.

Cordless drills
- Cordless drills start at around £13 for a 7.2V unit rising to £100-£130 for the latest 18V and £150+ for 24V versions.
- A good mid-range 9.6V or 12V drill should cost between £45 and £55.

Electric Screwdrivers
- A 2.4V driver can be found for under £10.
- One with a spindle lock for around £15.
- A 3.6V model with various accessories including a chuck costs around £20.
- A 3.6V model with torque control, spindle lock and accessories costs around £34.
- Cordless screwdrivers start at under £10 for a 2.4V unit rising to around £35 for a screwdriver with torque settings, carry case and additional screwdriver bits.

1. On a mains drill, the more Watts, the more power - but around 550W-650W will be more than adequate for most users.
2. A 10mm chuck on a mains drill will limit the size of drill bits and accessories - a model with a 13mm chuck may cost just £5 more. Keyless chucks are much more convenient and there's no key to lose!
3. Hammer action is useful on a cordless drill, but don't expect it to do the work of a mains drill.
4. On a cordless drill, more volts equals more drilling power - but adds to the cost. A 9.6V drill is a good compromise.
5. Fast chargers minimise downtime but cost more - consider a second battery if continuous use is envisaged.
6. Screwdrivers with continuous chargers will mean the tool is always ready for use.