Narrow standard parts

Narrow standard parts are standardized fasteners, which are actually a kind of connecting parts (connectors), but because of a wide variety of applications, they are only used in actual use, or even referred to as standard parts for short. It usually includes the following 12 types of parts:
1. Bolt: A type of fastener composed of two parts: head and screw (cylinder with external thread). It needs to be matched with nut to fasten and connect two parts with through holes. This type 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.
2. Stud: no head, only a type of fastener with external threads at both ends. When connecting, one end of it must be screwed into a part with an internal thread hole, and the other end must pass through a part with a through hole, and then screw on a nut, even if the two parts are fastened and connected into a whole. This type of connection is called a stud connection and is also a detachable connection. It is mainly used for occasions where one of the connected parts has a large thickness, requires a compact structure, or is not suitable for bolt connection due to frequent disassembly.
3. Screw: It is also a kind of fastener composed of two parts of the head and the screw. It can be divided into three categories according to the purpose: machine screw, set screw and special purpose screw. The machine screw is mainly used for the fastening connection between a part with a through hole and a part with a through hole. No nut is required (this connection form is called a screw connection, and it is also a detachable connection; It can also be matched with a nut for the fastening connection between two parts with through holes.) Set screws are mainly used to fix the relative position between two parts. Special purpose screws, such as eye screws, are used for hoisting parts.
4. Nut: with internal thread hole, the shape is generally flat hexagonal column, flat square column or flat cylinder, with bolts, studs or machine screws, used to fasten and connect two parts, making it a whole.
5. Self-tapping screws: similar to machine screws, but the thread on the screw is a special thread for self-tapping screws. It is used to fasten and connect two thin metal components to form a whole. Small holes need to be made on the components in advance. Due to the high hardness of this screw, it can be directly screwed into the holes of the components to form corresponding internal threads in the components. This connection form also belongs to detachable connection.
6. Wood screw: it is also similar to the machine screw, but the thread on the screw is a special wood screw thread, which can be directly screwed into the wood component (or part), and is used to fasten a metal (or non-metal) part with a wood component. This connection is also a detachable connection.
7. Washer: a type of fastener in the shape of a flat ring. It is placed between the supporting surface of the bolt, screw or nut and the surface of the connecting part to increase the contact surface area of the connected part, reduce the pressure per unit area and protect the surface of the connected part from damage; another type of elastic washer, It can also play a role in preventing the nut from loosening.
8. Retaining ring: for the shaft groove or hole groove of the machine and equipment, it plays the role of preventing the parts on the shaft or hole from moving left and right.
9. Pin: mainly for parts positioning, some can also be used for parts connection, fixed parts, transmission power or locking other fasteners.
10. Rivet: A type of fastener composed of two parts of the head and the nail shank, which is used to fasten and connect two parts (or components) with through holes to make it a whole. This type of connection is called rivet connection, or riveting for short. It is connected with non-detachable connection. Because to separate the two parts that are connected together, the rivets on the parts must be destroyed.
11. Assembly and connection pair: Assembly refers to a type of fastener supplied in combination, such as a combination of a certain machine screw (or bolt, self-supplied screw) and a flat washer (or spring washer, lock washer); Connection pair refers to a type of fastener supplied by a combination of a certain special bolt, nut and washer, such as a high-strength large hexagon head bolt connection pair for steel structure.
12. Welding nail: A heterogeneous fastener composed of a nail rod and a nail head (or no nail head), which is fixedly connected to a part (or component) by welding so as to be connected to other parts.