Under normal circumstances, what are the special screws for automobiles? The electroplating of the combination screw generally refers to the electroplating of the iron combination screw. Electroplating is divided into environmental protection and non-environmental protection. Commonly used combination screw electroplating colors include environmentally friendly color zinc, environmentally friendly blue zinc, environmentally friendly white zinc, environmentally friendly nickel, red color, white zinc, white nickel, etc. Cross recessed screws, hexagonal combination bolts and self-tapping combination screws have the same functions as the corresponding cross recessed screws, hexagonal head bolts and self-tapping screws. The main feature of these combination screws is that they are equipped with corresponding washers, which is very convenient to use.

As a whole, combined screws are commonly used in electrical, electricity, machinery, electronics, household appliances, furniture, ships, and so on. But the above said that different combination screws have different functions. For example, Phillips pan head combination screws are commonly used in small electronic products. Larger cross-external hexagonal combination screws are used in larger electrical products, such as inverters. For larger inverters, there are many cross-external hexagonal combination screws. Hit on the inverter case. To loosen the tightening effect. For example, the two-combination screw with flower teeth is used on the frequency converter to break the paint, so that all the two-combination screws on the chassis panel are energized. There is also a square crimping two-combination screw, which itself is a two-combination screw with a pan-head screw and a square pad. It is generally used on the terminal block. The role is for wiring, for crimping.

High-strength large hexagon head bolt combination screws for steel structure, mainly used for railway and highway bridges, boiler steel structures, industrial plants, high-rise civil buildings, tower mast structures, hoisting machinery and their steel structures require friction-type high-strength bolt combinations The place of the screw. Its characteristic is the bolt, which is called a dodecagon at the end of the bolt. When installing, a special electric wrench must be used. There are two socket heads on the top and bottom. One is sleeved on the hexagon of the nut, and the other is sleeved on the decagon of the outer hexagonal screw. When tightening, apply a clockwise torque to the nut, and apply an equal counterclockwise torque to the dodecagon of the bolt, so that the end of the hexagonal screw and the neck of the dodecagon will receive torsion shear until the neck is cut. So far, the installation is complete. This torsion-shear type high-strength hexagonal screw is a one-time use screw, and generally cannot be removed after installation.