Analysis: the concept and classification of common hardware standard parts

Hardware standard parts are standard parts made of metal. The following introduces the concept and classification of common hardware standard parts.

1. Bolt:

A type of fastener consisting of two parts, a head and a screw (cylinder with external threads), which need to be matched with a 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:

There is no head, only a type of fastener with threads on both ends. When connecting, one end of it must be screwed into the part with internal threaded hole, the other end must pass through the part with through hole, and then the nut is screwed on, even if the two parts are tightly connected as a whole. This type of connection is called a stud connection, which is also a detachable connection. It is mainly used 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 type of fasteners composed of two parts: the head and the screw. According to the purpose, it can be divided into three categories: machine screws, set screws and special purpose screws. The machine screw is mainly used for a tightly threaded hole part, and a fastening connection between a part with a through hole, no nut is required (this type of connection is called a screw connection, which is also a detachable connection; it can also be It is matched with a nut to fasten the connection between two parts with through holes.) The set screw is mainly used to fix the relative position between the two parts. Special purpose screws such as eyebolts are used for lifting parts.

4. Nut:

With internal threaded holes, the shape is generally a flat hexagonal column, but also a flat square column or a flat cylinder. It is used with bolts, studs or machine screws to fasten and connect two parts. Become 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 make them into a whole. Small holes need to be made in the component in advance. Because this kind of screw has high hardness, it can be directly screwed into the hole of the component. Form the corresponding internal thread. This type of connection is also a detachable connection.

6. Wood screws:

It is also similar to a machine screw, but the thread on the screw is a special wood screw thread, which can be directly screwed into the wooden component (or part) to connect a metal (or non-metal) part with a through hole with A wooden component is firmly connected together. This connection is also a detachable connection.

7. Washer:

A type of fastener with an oblate ring shape. It is placed between the support surface of bolts, screws or nuts and the surface of the connected parts, which increases the contact surface area of u200bu200bthe connected parts, reduces the pressure per unit area and protects the surface of the connected parts from damage; another type of elastic washer, It can also prevent the nut from loosening.

8. Retaining ring:

For installation in 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 used for parts positioning, and some can also be used for connecting parts, fixing parts, transmitting power or locking other fasteners.

10. Rivet:

A type of fastener consisting of two parts, a head and a nail rod, used to fasten and connect two parts (or components) with through holes to make them into a whole. This type of connection is called rivet connection, or riveting for short. Belong to and non-detachable connection. Because to separate the two parts connected together, the rivets on the parts must be broken.

11. Assembly and connection pair:

Assemblies refer to a type of fasteners 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); A type of fasteners supplied in combination of special bolts, nuts and washers, such as high-strength large hexagon head bolts for steel structures.

12. Welding nails:

A heterogeneous fastener consisting of a nail shaft and a nail head (or no nail head) is fixedly connected to a part (or component) by welding, so that it can be connected with other parts.