Hex bolts refer to fasteners composed of head and screw.
Bolts are divided into iron bolts and stainless steel bolts according to material, that is, hex head bolts (partially threaded) -C and hex head bolts (full thread) -C, also known as Hex head bolts (rough) wool hex head bolts, black iron screws.
1.According to the connection force method, there are ordinary and hinged holes. The bolts for hinged holes must match the size of the hole and are used when subjected to lateral force.
2. According to the shape of the head, there are hexagonal heads, round heads, square heads, countersunk heads, etc. Generally, countersunk heads are used where the surface after the connection is smooth without protrusions, because the countersunk head can be screwed into the part. The head can also be screwed into the part. The tightening force of the square head can be larger, but the size is large. Hex heads are the most commonly used.
In addition, in order to meet the need for locking after installation, there are holes in the head and holes in the rod. These holes can prevent the bolt from loosening when subjected to vibration.
Some bolts without threaded polished rods need to be thin, called thin waist bolts. Such bolts are conducive to the connection of variable forces.
There are special high-strength bolts on the steel structure. The head will be larger. The size will also change.
In addition, there are special uses: T-slot bolts, the most used on machine tool fixtures, special shape, both sides of the head must be cut off. Anchor bolts are used to connect and fix the machine and the ground. , As mentioned above and so on.
There are also special studs for welding. One end has a thread and one end is not. It can be welded to the part and the other side is directly screwed.