Screwdrivers

Phillips and Pozidriv have similar but not identical cross-shaped profiles: the Pozidriv has four extra notches between the arms of the cross. Using a Phillips on a Pozidriv screw, or vice versa, can damage the screw head and make the tip slip. Choose the matching profile and the right size, for example PH2 or PZ2, before driving the screw.

Precision sets with a slim handle and small tips are designed for watches, electronics and household appliances. The collection includes Wiha and Ingco ranges, to be chosen according to the screws you need to undo. The tips must fill the screw recess properly, otherwise the head gets damaged and the screw becomes difficult to remove.

The Torx profile has six star-shaped points and is used in cars, household appliances and mechanical components, because it transmits torque without slipping easily. There are also drilled Torx bits, with a hole in the centre of the tip. A Torx bit cannot be used on a cross-head or slotted screw, so check the profile before you start.

Ratchet screwdrivers and pistol-grip models let you drive or undo screws without repositioning your hand, which is useful for long screws or in tight spaces. Choose a model with interchangeable bits if you have to work with different profiles. Check the handle length and the size of the bits against the screws for your job.

A 6- or 7-piece set covers the most common sizes for home and maintenance work. Larger sets, of 26 or 37 pieces, add sockets and bits for different profiles, useful in a workshop. The number of pieces matters less than the type of profile: check that the sizes you really use are included.

The magnetiser makes the screwdriver tip magnetic, so the screw stays attached while driving and you can work even in awkward spaces. The demagnetiser does the opposite, removing the residual magnetism that attracts swarf and metal dust. Useful in the workshop and for precision work.

Slipping happens when the tip is the wrong size or worn: the tip must fill the whole recess of the screw. Press firmly on the screwdriver while driving and replace worn bits. For seized screws use a penetrating oil or an impact screwdriver, rather than forcing it with your hand alone.

For work on live parts you need insulated screwdrivers, made to IEC 60900 and marked with the working voltage. The screwdrivers in a standard set are not designed for this use. Do not use non-insulated screwdrivers on live installations, and follow the electrical safety procedures required.