A screwdriver is a tool used to twist a screw to force it into place. It usually has a thin wedge-shaped head that can be inserted into the slot or notch of the screw head - Beijing-Tianjin-Jin-Jin and Shaanxi-Shaanxi dialect "Jiangxi, Anhui, and Hubei, Henan, and Shaanxi are called "starters", the central and western regions are called "changing knives", and the Yangtze River Delta region is called "spinning chisels."
Technical principle editing
The screwdriver is used to paint the lid and utilizes the working principle of the lever. The greater the distance from the power point to the fulcrum, the more labor-saving, so the long screwdriver is more labor-saving than the short screwdriver.
The screwdriver is used to screw the screws to take advantage of the working principle of the axle. When the wheel is larger, the effort is less, so using a thicker screwdriver is more labor-saving than using a thin screwdriver to tighten the screw.
The Phillips and Phillips screwdrivers were invented by Henry Phillips in the 1930s. First used on the assembly line of the car. So Phillips and Phillips screwdrivers are also known as Philips screws and Phillips screwdrivers.
In order to apply a small torque to the slotted screw, it is thought that a slot is opened in the screw head, and the screw can be easily tightened and loosened with a corresponding one-shaped screwdriver, but with the rapid development of science and technology, the screw The application is becoming more and more widespread, and the shortage of screws and slotted screwdrivers is also present. First, once the slot of the screw head is damaged, the screw cannot be unscrewed. The longer the length of the slot, the easier it is to be destroyed during the screwing process. In order to shorten the length of the notch, improve the ability of the notch to resist damage, and transmit the same amount of torsion, it is thought that the same torque can be withstood by the cross groove, but the length of one notch is half short, resisting damage. The ability has been greatly enhanced. The screwdriver is originally a flat shape and cannot be used for the screw of the cross recess. Only another Phillips screwdriver and a Phillips screw are produced. There are two kinds of screwdrivers.
The slotted screws are used since the machine. It is impossible to replace the screws on the old machine. The Phillips screwdriver can not be used on a slot, and the slotted screw is still in production, so keep a flat-blade screwdriver. In this way, most of the new machines use cross-notch screws, and the old ones are still in use, and there are cases where two types of screwdrivers are used at the same time.