Like the screw, the bolt occupies an integral position in both industrial and everyday life. In fact, bolts and screws are used more than any other type of mechanical fastener, and they can be found in nearly every simple or complex machine. Although there is no absolute distinction, the difference between screws and bolts can be broadly defined as one of thread size and tapering. Bolts are generally larger and do not have tapered ends. In standard usage, a fastener that is torqued with a nut is usually considered a bolt.

Nuts are perforated metal blocks with internal or female threads which are used with bolts and some screws in order to secure components. There are many sizes and varieties of nuts; each with a particular fastening purpose. Some nuts can be applied without tools, and others may have special designs to prevent the nut from loosening.

Washers are thin plates of metal or non-metallic material with a hole, usually in the middle. These parts are normally used to relieve friction, prevent leakage, isolate, prevent loosening or distribute pressure of a nut, an axle bearing, or a joint.

Manufacturing process

Cold Forming 

Hot Forming

Cold Punching