1. Ordinary external hex-widely used, characterized by a relatively large tightening force, the disadvantage is that there is enough operating space during installation, you can use a spanner or open-end wrench, or a spanner above the eyeglass wrench Large operating space.
2. Hexagonal head with cylindrical head-it is the most widely used among all screws. Because of its relatively large tightening force, it can be operated using a hexagonal wrench. It is very convenient to install, almost used in various structures, and has a beautiful and neat appearance. The disadvantage is that the tightening force is lower than the outer hexagon. In addition, the repeated use can easily damage the inner hexagon and cause it cannot be removed.
3. Pan head hexagon-rarely used mechanically, mechanical properties are the same as above, mostly used in furniture, the main role is to increase the contact surface with wooden materials and increase the ornamental appearance.
4. Headless internal hexagon-must be used on some structures, such as the top wire structure that requires a large topping force, or where the cylindrical head needs to be hidden.
5. Countersunk head hexagon-mostly used in power machinery, the main function is the same as the hexagon
6. Nylon lock nut-a nylon rubber ring is embedded in the hexagonal surface to prevent loosening of the thread. It is used on strong power machinery.
7. Flange nut-mainly used to increase the contact surface with the workpiece, mostly used in pipes, fasteners and some stamping parts and castings.
8. Ordinary external hexagon nuts-the most versatile and one of the most common fasteners.