Screwdriver

A screwdriver is a device used to manipulate screws. There are many varieties, two are pictured here, the flathead and the phillips head.

A flat head screwdriver A typical flat head manual screwdriver.

A Phillips head screwdriver A Phillips head screwdriver.

Screwdrivers come in a large variety of sizes to match those of screws, from tiny jeweller's screwdrivers up. It is important to use a screwdriver that is the right size and type for the screw used, or it is likely that the screw will be damaged in the process of inserting it. When tightening a screw with force, it is important to press the head hard into the screw, again to avoid damaging the screw.

Many screwdriver designs have a handle with detachable head (the part of the screwdriver in contact with the screw), allowing a set of one handle and several heads to be used for a variety of screw sizes and types. This kind of design has allowed the development of electrically-powered screwdrivers, which as the name suggests use an electric motor to rotate the bit.

Many contemporary electrical appliances, if they use screws at all, use Torx screws with oddly-shaped heads in an attempt to prevent users of the device disassembling them - see the article on screws for details. However, screwdrivers specifically designed for these special screws have become widely available in electronics stores.

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Screwdriver is also the name of a type of cocktail: see screwdriver cocktail