A tamper proof screwdriver is not a screwdriver that is resistant to tampering, but rather a specialized screwdriver for installing and removing tamper proof screws. Many varieties of tamper proof screwdriver exist, as each tool can usually install and remove only a single type of screw, and there are many different varieties of tamper proof screw on the market. This term may refer either to a conventional hand tool or to a screwdriver bit that is meant to be used in an electric drill or screwdriver.
Ordinary screws can be removed just as easily as they can be installed, and this is one of their great advantages. In some cases, however, vandalism and tampering are serious concerns, and ordinary screws are not suitable. Many public restrooms use tamper proof screws, as these areas suffer from frequent vandalism. In other cases, such as in engines or in areas related to safety or security, tampering is less common, but the consequences are potentially severe. Tamper proof screws are often used in these areas as well.
One common variety of tamper proof screwdriver is designed to drive screws with very unusual drive shapes. These oddly-shaped screws can be easily tightened or loosened, but ordinary standard or Phillips head screwdrivers will not align correctly with the head of such a screw. Many manufacturers sell sets of screwdriver bits that contain a selection of the most common sorts of oddly-shaped bits.
A second type of tamper proof screwdriver is designed to work with altered versions of conventional screws. A common technique involves adding a dot of metal to the middle of the cross formed by a normal Phillips head. This prevents an ordinary screwdriver from being used to tighten or loosen such a screw. A tamper proof screwdriver designed to be used with this type of screw is specially shaped so that it can accommodate the extra dot of metal, and still grip the screw properly. This technique is used to make many types of screw more tamper resistant.
Using a tamper proof screwdriver is simple. These tools are designed to match perfectly with the screws that they are meant to drive. If the correct tool is available, then tamper proof screws should be as easy to work with as any other variety of screw.
Tamper proof screwdrivers are of no help when dealing with one way screws. These screws can be installed with an ordinary, standard screwdriver but have heads that slope gently up in the direction that a screwdriver would need to press in order to loosen the screw. No screwdriver, tamper proof or otherwise, can easily remove these screws. Pliers or other less elegant tools must be used instead.