hot dip galvanizing Hex bolt DIN931 class 10.9 half thread 933 full thread grade 10.9

1.DIN931 Definition and standard of bolts ‌

DIN931 is the standard code for German standard hexagon head thick rod semi-threaded bolts, suitable for bolts with nominal diameters ranging from M1.6 to M39. The materials are typically carbon steel or alloy steel, and surface treatments include oxidation, blackening or galvanizing

2.The difference between DIN931 and DIN933 ‌

Youdaoplaceholder0 DIN931‌ : thick rod half-threaded bolt (partial thread);

Youdaoplaceholder0 DIN933‌ : full thread bolt. Both are German standards, but their thread coverage ranges are different

3.The strength grade of DIN931 bolts is ‌

Common grades include 4.8 grade, 8.8 grade, 10.9 grade and 12.9 grade. Among them, 12.9 grade is a high-strength bolt, suitable for high-load scenarios such as machinery and construction

4.Calculation of the thread length of DIN931 bolts ‌

The thread length (b) is related to the nominal length (L). For example, the reference value of the thread length for an M12 bolt is:

When L≤125mm, b=30mm;

125< When L≤200mm, b=38mm

5.The size specification of DIN931 bolts is ‌

Youdaoplaceholder0 Diameter range ‌ : M1.6-M39 (Non-preferred sizes such as M3.5, M7, etc. require special marking)

The width of the opposite side of the head (s) ‌ : for example, for an M12 bolt, s=18mm