Combination screw refers to a combination of a screw with a spring washer and a flat washer by rubbing the teeth to fasten the assembly together. The two-component screw refers to a two-component screw with only one spring washer or only one flat washer. If so, it can also be equipped with a two-component with only one tooth.

Electroplating of composite screws Generally, the electroplating of composite screws generally refers to the electroplating of iron composite screws. Electroplating is divided into environmental protection and non-environmental protection. Commonly used combination screw electroplating colors are environmentally friendly color zinc, environmentally friendly blue zinc, environmentally friendly white zinc, environmentally friendly nickel, red color, white zinc, white nickel and so on. The purpose of cross recessed combination screws, hexagonal combination bolts and self-tapping combination screws is the same as that of 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.

Combination screw use
High-strength large hexagonal 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 In the case of screws. It is characterized by a bolt, which is called a dodecagon at the end of the bolt. When installing, you must use a special electric wrench with 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 are subjected to torsion shear until the neck is sheared. So far, the installation is over. This torsion-shear type high-strength hexagonal screw is a one-time use screw, and generally cannot be removed after installation.