The characteristics of the power bolt are generally used in the local area where the surface lubrication is not raised after the connection is required, because the countersunk head can be screwed into the part. The round head can also be screwed into the part.
The tightening force of the square head can be larger, but the size is large. In order to meet the needs of post-installation locking, there are holes in the head and holes in the rods, which can prevent the bolt from being loosened when it is oscillated. Some bolts without threads are to be thin, called thin waist bolts. This type of bolt facilitates the coupling of the force. There are special high-strength bolts on the steel structure, the head will be larger and the size will change. Others have special uses: T-slot bolts, the most used on machine tool fixtures, special shape, cut off on both sides of the head. Anchor bolts for the machine and the ground are fixed and have many shapes. U-bolts, as mentioned above. and many more. There is also a special stud for welding, one threaded at one end, can be welded to the part, and the other side is directly screwed