Grade
According to the tensile strength and yield strength of the bolt, it can be divided into 4.8, 6.8, 8.8, 10.9, 12.9 and so on.
Grade 4.8 bolts are mostly made of unprocessed round steel, the specifications and models may not be accurate enough, and the appearance is rough. The installation is more convenient and the production cost is lower. It is mostly used for temporary fixing during tensile connection or installation, and occasions with low performance requirements.
The manufacturing process of Grade 6.8 bolts has been improved from Grade 4.8, but it may still maintain a certain economy and practicality. Suitable for medium strength connection requirements.
This high precision machining method of Grade 8.8 ensures the high quality performance of the bolts, but correspondingly increases the complexity of manufacturing and installation, resulting in higher prices. Grade 8.8 and above bolts are mostly CNC machining technology, the surface is smooth, the specifications are accurate, and they are often subjected to special surface treatment (such as blue treatment) to improve their corrosion resistance and beauty.
Grade 10.9 and 12.9 bolts are used in applications that require very high connection performance due to their high strength and toughness, such as the connection of important mechanical equipment and the installation of key automotive parts.
Grade 4.8 bolts are mostly made of unprocessed round steel, the specifications and models may not be accurate enough, and the appearance is rough. The installation is more convenient and the production cost is lower. It is mostly used for temporary fixing during tensile connection or installation, and occasions with low performance requirements.
The manufacturing process of Grade 6.8 bolts has been improved from Grade 4.8, but it may still maintain a certain economy and practicality. Suitable for medium strength connection requirements.
This high precision machining method of Grade 8.8 ensures the high quality performance of the bolts, but correspondingly increases the complexity of manufacturing and installation, resulting in higher prices. Grade 8.8 and above bolts are mostly CNC machining technology, the surface is smooth, the specifications are accurate, and they are often subjected to special surface treatment (such as blue treatment) to improve their corrosion resistance and beauty.
Grade 10.9 and 12.9 bolts are used in applications that require very high connection performance due to their high strength and toughness, such as the connection of important mechanical equipment and the installation of key automotive parts.
