DIN 933 - 1987 Hexagon Head Screws Threaded Up To The Head - Product Grades A and B
This standard specifies requirements for M1,6 to M52 hexagon head screws threaded up to the head, assigned to product grade A, for sizes up to M24 and lengths not exceeding 10d or 150 mm, and to product grade B for sizes greater than M24 or lengths exceeding 10 d or 150 mm.
For thread sizes not greater than M4,also permitted without chamfered end