Screw drivers, also known as screw chisels, screwdrivers, screwdrivers, and screwdrivers, are tools for tightening and removing screws. There are many styles and specifications of screw drivers, and commonly used ones include Phillips screw drivers, Phillips screw drivers, grip screw drivers, multi-purpose screw drivers, and hex socket screw drivers.
（1） Phillips screwdriver
The Phillips screwdriver is used to tighten or remove slotted screws and wooden screws. The through-hole slotted screw driver can withstand large torques and can be used by striking with a hammer at the tail end; The square screw screwdriver can also be clamped with a corresponding wrench to increase torque. Its structure is shown in Figures 1-25.
Specification for screwdriver for straight head screws - Rod length for use × The diameter of the rotary rod is expressed in millimeters. According to the structure of the handle, it can be divided into two types: ordinary type and through type; According to material, it can be divided into wooden handles and plastic handles; In addition, there are square screwdrivers and short and thick screwdrivers. Its specifications are shown in Table 1-11.
（2） Cross slot screw driver
The cross shaped screw driver is used for disassembling cross groove screws. Its structure is shown in Figures 6-26.
Specification for cross shaped screw drivers - Rod length for use × The diameter of the rotary rod is expressed in millimeters. Its specifications are shown in Table 1-12.
（3） Clamp handle screw screwdriver
Due to its ability to withstand high torque, the clamp handle screw driver can not only be used to tighten or disassemble slotted screws, wooden screws, and self tapping screws, but also to be used as a chisel when struck at the tail or in the absence of an electric field. Its structure is shown in Figures 1-27.
The specification of the grip screw screwdriver refers to the total length of the screwdriver (mm). There are four commonly used specifications: 150200250300mm.
（4） Multipurpose screw driver
Multi purpose screw drivers are used to tighten or disassemble various forms of slotted screws, wooden screws, and self tapping screws, and can drill wooden screw holes and be used as test pens. Its structure is shown in Figures 6-28.
The specification for multi-purpose screw drivers refers to the total length of the driver (mm). Its specification is 230mm.
（5） Internal hexagonal screw driver
Internal hexagonal screw drivers are used to tighten or remove internal hexagonal screws. Its structure is shown in Figures 1-29.
The specifications of the hexagon socket screw driver are shown in Table 1-13.
（6） Precautions for using screw drivers
1. When using screw drivers, appropriate types and specifications should be selected based on the screw groove. The working part of the driver must match the groove type and groove to prevent damage to the groove.
2. The end of a regular screwdriver cannot be struck with a hammer, and the screwdriver cannot be used as a chisel, pry bar, or other tool.
When using a screwdriver to tighten or disassemble live screws, do not touch the metal rod of the screwdriver with your hands to avoid electric shock accidents.
To prevent the metal rod of the screw driver from touching the skin or adjacent charged objects, an insulating tube should be placed on the metal rod.
5. Electricians should not use screw drivers with metal rods directly leading to the handle top, otherwise it is easy to cause electric shock accidents.
6. After the blade of the screw driver becomes round over time, it can be polished on a grinding stone. Do not polish on the grinder to avoid losing rigidity during annealing.
