DIN 912 (ISO4762) Hexagon socket bolts are also called cup-head hexagon socket bolts. The shape is cylindrical head and the groove is hexagon socket polygon. Hexagon socket head bolts are widely used in mechanical installation because they are easy to fasten and disassemble, and are not easy to slip.
DIN 912 Product Details
DIN 912 Hexagon socket head bolts should be installed and disassembled using a hexagonal wrench. It is a tool with a 90° bending. It is divided into long and short sides. When the short side is used to install the screw, the longer side can be used to hold the smaller The force can achieve the function of tightening screws. The long end of the tool is generally used for the installation and removal of screws at the assembly deep hole position.
The thread diameter is generally M1.4-M64 grade A metric products. Thread tolerance is generally 6g, 12.9 grade is 5g6g. The materials on the market are generally carbon steel CL8.8/ 10.9/ 12.9 grade.
The surface treatment is generally black and galvanized. In recent years, due to the environmental protection requirements, the surface coating has been upgraded, with the appearance of trivalent chromium-based electroplating layer and non-electrolytic flake zinc coating instead of DAC
zinc flake, silver (ZFSHL)-flake zinc coating, silver, with a lubricating sealing layer. Since this coating does not contain hexavalent chromium, it can be mainly used for commercial vehicle assembly, construction machinery and agricultural vehicle equipment with anti-corrosion requirements field.
zinc-nickel, silver (ZNSHL)-zinc-nickel alloy coating is a zinc-nickel alloy coating that does not contain hexavalent chromium, with a lubricating seal layer. There are mainly two zinc-nickel, silver (ZNSHL) zinc-nickel alloy black and silver, namely ZNBHL and ZNSHL, Mainly used in high-risk corrosive environments, but also has a certain decorative nature.
thick-film passivated (ZSML)-a thick-film passivated coating that does not contain hexavalent chromium. It is used to replace trivalent chromium. It belongs to environmentally friendly zinc plating with a closed lubricant layer. This coating can better replace ordinary galvanizing such as A2C\A3C, etc.
Other non-electrolytic zinc flake coatings: GEO-zinc-aluminum coating-because DAC contains hexavalent chromium, it is gradually being replaced by GEO. GEO-related coatings mainly include GEO500A and GEO321+VL.
About DIN912/ISO4762 hexagon socket bolt inspection:
In different use environments, the quality of the product needs to be tested for some specific items to ensure that it meets the needs of customers and the safety in use. The general inspection items include mechanical inspections in addition to common appearance inspections and basic inspections such as pass-stop rules. And chemical testing. Such as tensile test, impact test, surface hardness and core hardness, torsion test, salt spray test, etc.