Twist screwdriver is a device used to turn the screw to force them to put in place the tools, there is usually a thin wedge-shaped head, screws can be inserted in the slot or notch – also known as the "screwdriver". There are words major (minus) and cross (plus sign) in two ways. Also common are hexagonal screwdriver, include both hex and hex. Screwdriver and distinguish it from the traditional screw driver (English: the Screwdriver) and ratchet screwdriver (electric screwdriver) (English: Ratchet screwdriver). Traditional hand screwdriver is made of a plastic bar plus a lock screw and ratchet screwdriver consists of a plastic handle and a ratchet mechanism. Who could let the lock screw Rod clockwise or counterclockwise racing, idling through the function of promoting the efficiency of locking screws, instead of successive power drive (hand) back to the original position. Use: fixed phone, open the Cabinet need to use a screwdriver (some mobile phone case is snap lines don't have the screwdriver). Most use screws with Hexagon screws; different handsets have different specifications, generally T5, T6, T7, T8, and some models are equipped with a special screw, you need to use special screwdriver. There was also a need to prepare some small words, small Phillips-head screwdriver. In the selection of such tools, but should choose a, b, which includes almost all mobile phone shell tools. When you open the Cabinet, according to the type of fixing screws on the casing and use an appropriate screwdriver specifications. If the selection is not appropriate, it may screw flat screw slot, slipping phenomena. Usage: the screwdriver has a special shape at the end of the screw top of the pits, fixed, and then start the rotation handle. According to specifications, Rotate clockwise to block tight; counterclockwise or walk out. A screwdriver can be used in the cross screws. But Philip ' has a strong resistance to deformation. Screwdriver type 1, ordinary screwdriver: is the head handle-made of screwdrivers that are easy to prepare, just get out of it, but because there are many screws of different lengths and thickness, sometimes need to prepare many different types of screwdrivers. 2, combination screwdriver: a screwdriver screwdriver head and handle separately, when you want to install different types of screws, simply replace head screwdriver you can, no need to carry a large screwdriver. Benefit is that you can save space, but easily lost screwdriver head. 3, electric screwdriver: electric screwdriver, as the name suggests is based on electric motors replace the manual install and remove screws, usually a combination screwdriver. 4, watch screwdriver: a precision screwdriver, commonly used in repairing hand strap watches, so have said this. 5, boy screw driver head shank and length dimensions smaller than the commonly used screwdrivers, non-clock opener. From its shape, usually include the following: 1, straight. This is the most common type. 2, l-shaped. More common in hex, using its long rods to increase torque, thus more efficiently. 3, t-shaped. Automobile maintenance industry is widely used.