The combination bolt refers to a three-assembly assembly consisting of an external hexagonal bolt, a spring washer and a flat washer, which are fastened together with threaded threads. Combination bolts are also called external hexagonal combination screws, also called hexagonal combination bolts.

The production process of combined bolts is to first punch out the external hexagonal bolt piers, and then put on the elastic flat pads in a manual or automatic pad threading machine. Then he was rubbing his teeth. If the quantity is large, an automatic pad threading machine is used. If the quantity is too small, workers usually thread elastic flat pads. Of course, the elastic flat washers used in combination bolts are generally used professionally to make combination screws. Other commonly used spring washers and flat washers cannot be used for combination screws. So many of them are customized elastic flat pads. The choice of elastic pad material is very important. To choose a good spring pad, material like Mn65 is good. If a bad spring washer is assembled on the combination screw, it will easily break, or it will be pressed down and unable to spring up.