This standard specifies hexagon head bolts whose thread specifications are M1.6~M64, property class are class 5.6, 8.8, 9.8, 10.9, A2-70, A4-70, A2-50, A4-50, CU2, CU3 and AL4, product grade are grades A and B. Those of grade A are used in bolts that d=1.6~24 mm and 1≤10d or z≤150 mm (for smaller value); those of grade.
B are used in bolts that d>24 mm or 1>10d or 1>150 mm (for smaller value)
If other technical requirements are required, they shall be selected from current standards (such as GB/T 196, GB/T 3106, GB/T 3098.1, G3/T 3098.6 and GB/T 3103.1).
