1. General hexagonal: a wide range of uses, features is a large tightening force, the disadvantage is to have enough operating space in the installation, the installation can use a spanner or open wrench.
2. Hexagonal cylinder head: is the most widely used of all screws, the tightening force is greater, because he can use the hexagonal key operation, installation is very convenient, failure than the outer hexagonal tightening force slightly lower.
3. Hexagonal head: rarely used for machinery, more for furniture, the main role is to increase the contact with wood materials and increase
4. Nylon lock nut: hexagonal face is embedded with nylon rubber ring to prevent loose thread structure. Suitable for high power machinery.
5. Flange nut: mainly plays the role of increasing the contact surface with the workpiece, mostly used for pipes, fasteners have some stamping parts and castings.