What's kind of iron and steel is suitable for real grade 12.9 hex socket screws

Grade 12.9 bolts and screws refer to ultra high strength screws made of 35CrMo, 42CrMo, and B7 alloy steel materials, with a minimum tensile strength of 1220Mpa and a hardness of 39-44HRC. It is mainly used in the textile, hydraulic, injection molding, and machinery industries domestically.

1. The 12.9 grade screw refers to an ultra-high strength screw made of SCM435 alloy steel material, with a minimum tensile strength of 1220Mpa and a hardness of 39-44HRC. It is mainly used in the textile, hydraulic, injection molding, and machinery industries domestically.

2. According to the item, it can be divided into various types such as 12.9 grade external hexagonal bolts, 12.9 grade internal hexagonal head screws (cup head), 10.9 grade countersunk head internal hexagonal screws (flat cup), 10.9 grade semi round head internal hexagonal screws (round cup), 12.9 grade set screws (machine meter), 12.9 grade internal hexagonal plug screws, etc. According to the thread, it is divided into coarse thread, fine thread, metric, British, American, etc.

3. Grade 12.9 is the top variety of screws, with high hardness and tensile strength. Its Rockwell hardness (HRC) can reach 39-44, and its tensile strength can reach 1220N/mm2. However, due to the different shapes of screw manufacturing, countersunk hex screws (flat cups) and half round headed hex screws (round cups) produced from the same material can only achieve the minimum tensile strength of grade 10.9. It can also fully meet the high requirements of industrial and mining enterprises for fasteners in special occasions and components.

Ningbo Zhongli bolts manufacturing co.ltd only supplies real grade 12.9 Hex socket screws DIN912,ISO4762, the factory has 21 years production experience.