Don’t be confused about the three concepts of bolts, screws and screws!

Standard fasteners are divided into twelve categories. The selection is determined according to the use occasion and function of the fastener.
1. Bolt. Bolts are widely used in detachable connections in machinery manufacturing and are generally used with nuts (usually plus a washer or two washers).
2. Nut    Used in conjunction with bolts for tightening.
3.Screws Screws are usually used alone (sometimes with washers), generally for tightening or fixing, and should be screwed into the internal threads of the machine body.
4.Studs Studs are mostly used to connect places where one of the connected parts is thick, requires a compact structure, or is not suitable for bolt connection due to frequent disassembly. Studs are generally threaded on both ends (single-head studs are threaded on one end). Usually one end of the thread is firmly screwed into the component body, and the other end is matched with the nut to play the role of connection and tightening, but in many cases To a large extent, it also has the function of setting distance.
5. Wood screws Wood screws are used to screw into wood to join or fasten.
 6. Self-tapping screws The working screw hole matching the self-tapping screw does not need to be tapped in advance. The internal thread is formed while the self-tapping screw is screwed in.
7. Washer Washers are placed between the supporting surface of bolts, screws, nuts, etc. and the supporting surface of the workpiece to prevent loosening and reduce the stress on the supporting surface.
8. Back-up ring Back-up rings are mainly used to position, lock or prevent parts on the shaft or in the hole.
9.Pin Pins are often used for positioning, but also for connecting or locking parts, and as overload shearing elements in safety devices.
10. Rivets The rivet has a head on one end and an unthreaded stem. When in use, insert the rod into the hole of the connected piece, and then rivet the end of the rod to connect or tighten.
11.Connect Vice The connection pair is a combination of screws or bolts or self-tapping screws and washers. After the washer is installed on the screw, it must be able to rotate freely on the screw (or bolt) without falling off. Mainly plays the role of tightening or tightening.
12. Others Mainly includes welding nails and other contents.