Bolts are commonly used fasteners in mechanical connections. There are many types. According to different classification standards and application scenarios, they can be divided into the following categories:
1. Classification by head shape
Hexagonal head bolts: The head is hexagonal, which is easy to turn with a wrench. It is the most common type of bolt.
Countersunk head bolts: The head can be buried in the component, suitable for connections that need to ensure the plane.
Round head bolts: The head is round and suitable for some special occasions.
Square head bolts: The head is quadrangular and suitable for occasions where mechanical properties are not required.
2. Classification by use
Ordinary bolts: Used for general structural connections, such as hexagonal head bolts.
High-strength bolts: Used in occasions that need to bear large loads, such as high-strength bolts for steel structures.
Anchor bolts: Used to fix machinery and equipment on concrete foundations, including ordinary anchor bolts, right-angle anchor bolts, etc.
Eyebolts: with eye shape, used for threading wire ropes or hanging hooks, suitable for lifting equipment.
3. Classification by thread type Full thread bolts: The entire length of the screw is threaded, suitable for situations where full-length tightening is required.
Non-full thread bolts: The screw part is threaded, suitable for situations where partial tightening is required.
4. Classification by special functions Self-tapping screws: No need for pre-tapping, internal threads are automatically formed when screwed in, suitable for thin metal components.
Set screws: used to fix the relative position of parts, with a head with a slot, hexagonal, etc.
Expansion bolts: used to fix equipment in concrete or walls, and tightening is achieved through expansion.
5. Classification by material and application scenario Steel structure bolts: used for connecting steel structures such as buildings and bridges, such as high-strength bolt connection pairs.
Wood screws: used to screw into wood, with a slotted or cross-shaped head.
U-bolt: U-shaped, used to fix tubular or sheet objects, such as water pipes or automobile leaf springs.
6. Classification by specification model
The specification model of the bolt is usually represented by the letter "M", followed by a number indicating the nominal diameter, such as M6, M8, etc.
Summary: There are many types of bolts, and the selection needs to be considered comprehensively based on specific application scenarios, force requirements, material properties and other factors. For example, high-strength bolts are suitable for buildings and bridges, while self-tapping screws are suitable for the connection of thin metal components.
