Fasteners are parts that must be used in mechanical design, so what are the commonly used fasteners and what is the difference?
bolt
Composition: a type of fastener consisting of two parts: head and screw (cylinder with external thread),
Necessary matching parts: need to be matched with the nut;
Due to fastening: used to fasten and connect two parts with through holes
Connection method: This type of connection is called bolt connection.
Disassembly performance: detachable connection.
Stud
Composition: There is no head, only a type of fastener with threads on both ends.
Necessary matching parts: nuts need to be screwed on;
For fastening: one end must be screwed into the part with internal threaded hole, and the other end must pass through the part with through hole
Connection method: This type of connection is called stud connection.
Disassembly performance: detachable connection.
Main application: Mainly used in the 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
Screw:
Composition: A type of fasteners composed of two parts: head and screw,
Classification: According to the purpose, it can be divided into three categories: machine screws, set screws and special purpose screws.
1. Machine screws:
Used for fastening: mainly used for a fastening threaded hole part, and a fastening connection between a part with a through hole, (two through holes are also available)
Necessary leather fittings: no nuts required; (nuts required for through holes)
Disassembly performance: can be disassembled
2. Set screws are mainly used to fix the relative position between two parts.
3. Special purpose screws such as eyebolts are used for lifting parts
Nut
Composition: With internal threaded holes, the shape is generally flat hexagonal cylinder, but also flat square cylinder or flat cylinder, with bolts, studs or machine screws.
Connection method: used to fasten the connection of two parts to make them into a whole.

Self-tapping screws
Appearance: similar to machine screws, but the thread on the screw is a special thread for self-tapping screws.
Connection method: Used to fasten and connect two thin metal components to make them into a whole. Small holes need to be made on the components in advance. Because this kind of screw has high hardness, it can be directly screwed into the hole of the component. Responsive internal threads formed in the component
Wood screws:
Shape: It is also similar to machine screws, but the thread on the screw is a special wood screw thread.
Connection method: It can be directly screwed into the wooden component (or part) to fasten a metal (or non-metal) part with a through hole and a wooden component. This connection is also a detachable connection.
washer
Shape: A type of fastener with an oblate ring shape.
Connection method: placed between the supporting surface of the bolt, screw or nut and the surface of the connecting part,
Main function: It can increase the contact surface area of ​​the connected parts, reduce the pressure per unit area and protect the surface of the connected parts from damage; another type of elastic washer can also prevent the nut from loosening
rivet:
Composition: A type of fastener composed 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.
Connection: This 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.