DIN7990 hexagonal head bolts, steel structure design, surface hot-dip galvanized treatment, mechanical properties reaching grade 6.8 standard

1.What is the material standard for DIN7990 bolts?

This standard bolt is typically made of carbon steel (such as grade 4.8 /8.8) or stainless steel (such as A2-70), depending on the strength and corrosion resistance requirements of the application scenario.

2.What are the main application fields?

It is widely used in scenarios such as mechanical manufacturing, automotive assembly, and steel structure connection, and is particularly suitable for the fixation of precision equipment that requires high preload.

3.What is the difference from ordinary bolts?

DIN7990 is a fine-thread standard. Compared with coarse-thread bolts, it has higher vibration resistance and more precise dimensional control, but its manufacturing cost is relatively high.

4.How to choose the correct specification?

The diameter (M5-M24 is common) and length should be determined based on the thickness of the connecting parts, the magnitude of the force and the environmental conditions. It is recommended to refer to the load calculation table in the standard.

5.What are the options for surface treatment methods?

This includes galvanizing, Dacromet coating, phosphating, etc. Stainless steel or hot-dip galvanizing treatment is recommended for outdoor or corrosive environments.

6.What key points should be noted during installation?

A torque wrench must be used to control the preload to prevent the threads from stripped due to overload. It is recommended to use it in conjunction with anti-loosening gaskets to enhance reliability.