Fasteners in the market is also known as standard parts, is the two or more than two parts (or components) fastening connection into a whole when the use of a class of mechanical parts. Fasteners include 12 categories:
1. Rivet: It is composed of two parts: rivet shell and rod, which is used to fasten and connect the plate with two through holes to achieve the whole effect. This form of connection is called rivet connection, or riveting for short. Riveting is a non-removable connection because the rivets on the part must be broken to separate the two parts that are joined together.
2. Bolt: A type of fastener consisting of a head and a screw (a cylinder with an external thread), which should be fitted with a nut to fasten and connect two parts with a through hole. This form of connection is called bolt connection. If the nut is unscrewed from the bolt, the two parts can be separated, so the bolt connection is a detachable connection.
3. Stud: a type of fastener with no head and only external threads at both ends. When connected, one end of it must be screwed into the part with an internal threaded hole, the other end through the part with a through hole, and then screw on the nut, even if the two parts are fastened together into a single body. This form of connection is called stud connection, which is also a detachable connection. It is mainly used in the occasions where one of the connected parts has a large thickness, requires a compact structure, or is not suitable for bolted connection due to frequent disassembly. ,
4. Nuts: with internal threaded holes, the shape is generally shown as a flat hexagonal column, there are also flat square column or flat cylindrical, with bolts, studs or machine screws, used to fasten and connect the two parts, so that it becomes a whole.
5. Screw: also by the head and screw two parts of a type of fastener, according to use can be divided into three categories: machine screw, set screw and special purpose screw. Machine screws are mainly used for the fastening connection between a part with a tight threaded hole and a part with a through hole, without nut fit (this connection form is called screw connection, also belongs to the removable connection; Can also be fitted with a nut for a tight connection between two parts with a through hole. The setting screw is mainly used to fix the relative position between two parts. Special purpose screws such as lifting ring screws are used for lifting parts.
6. Tapping screw: similar to machine screw, but the thread on the screw is for special tapping screw thread. Used for fastening and connecting two thin metal components, so that they become a whole, the component needs to make a small hole in advance, because this screw has high hardness, can be directly screwed into the hole of the component, so that the component of the formation of a response to the internal thread. This form of connection is also a detachable connection.
7. Welding nails: because of light energy and nail head (or no nail head) composed of different fasteners, with welding method to fix it on a part (or component), in order to connect with other parts.
8. Wood screw: It is similar to machine screw, but the thread on the screw is special wood screw rib, can be directly screwed into the wood component (or part), used to fasten a metal (or non-metal) part with a through hole and a wood component together. This connection is also a removable connection.
9. Gasket: a type of fastener with an oblate annular shape. Between the supporting surface of bolts, screws or nuts and the surface of the connecting parts, plays a role in increasing the contact surface area of the connected parts, reducing the pressure per unit area and protecting the surface of the connected parts from damage; Another kind of elastic washer can also play a role in preventing the nut from loosening.
10. Retaining ring: for installation in the shaft groove or hole groove of the machine and equipment, playing the role of preventing the shaft or hole on the parts to move around.
11. Pins: mainly used for positioning parts, some can also be used for parts connection, fixing parts, transferring power or locking other fasteners.
12. Assemblies and connecting pairs: assemblies refer to a class of fasteners supplied in combination, such as a machine screw (or bolt, self-supplied screw) and flat washer (or spring washer, lock washer) combination supply; Coupling pair refers to a class of fasteners that are supplied in combination with a special bolt, nut and washer, such as high-strength large hexagon head bolt coupling pair for steel structure.
