Fastener is a kind of mechanical accessary that used to connecting and fastenning, which is widely used in many areas. It has a large number of types with different function and usage and has the features of stardardization, system and universal. As the reason,the fastener under the national or industrial standard is called standard fastener.

According the differences specifications of size, tolereance, weight, function, surface and mark. and the requirment of test and packing, there are DIN, BS, ANSI, GB standard etc .

Fastener is the most widely used mechanical components. With the develpment of international trade after we entered into the WTO in 2001, the fastener has been exported to worldwide for a large volume and the fastener of foreign manufacturers also swarm into our market. As one of the large volume export products, it has great meaning for us to participate international collaboration and competition.

Fastener is a glossay of the mechanical components which widely used to connect or fasten two or more parts. In the market, we also call the fasterner which meet the national standards or industrial standards as Standard Component.
Generally, the fastener can be the following types:

1. Bolt, it consist of head and pole ( cylinder with thread ) and work in with nut to connect two parts with hole. the connection way is called bolt connection, this connection way can be separate, so Bolt Connection belong to Disassembly Connection.

2. Stud, it has thread in the doulbe end and without head.　one end can screw into one parts with thread hole, the other end put through parts with hole and fastened by nut. So, the two parts were be connected. This is stud connection, it also belong to dissassembly connection, which is mainly used in the condition that one part is thick and the struction is compact or it should be disassembly frequently, it"s not fit for bolt connection.

3. Screw, it also consist of two parts, head and pole. It can be classified three types by usage: machine screw, set screw and screw with special purpose. Machine screw mainly used to connect with the components with thread hole,no need nut(when connect two component with hole, nut is needed ). this connection way is also belong to disassemble connection. set screw used to set the relative position of two components. Screw with special purpose , such as lifting screw used as suspension assemble component.

4. Nut, it has thread hole, usually, the shape is hexagon. it use together with bolt, stud or machine screw to connnect and set two components.

5. Tapping Screw, it similiar with machine, but the thread in the pole is special tapping screw thread.It used to connect two thin metal parts with small hole. because the screw is hardened enough to screw in to the metal parts and make thread in the hole match the screw. This is also belong disassebly connetion.

6. Wood Screw, it similiar with wood screw. but the thread is special wood thread. it can screw into wood parts.it used to connect one metal or non mental component with hole to one wood parts. this is also disassemble connection.

7. Washer, it used in the groove of machine and equipment to prevent the component above the hole or axes from shifting.

8. Pin. it mainly used to fix component. some can used to connection, transfer power or lock the other fasten component.

9. Rivet, it"s a kind of fastener consist of head and pole, which used to connect two components with hole, this way of connection is called rivet connection, this is undisasseblly connection. If you want to separate the two connected parts, the rivet must be damaged.