Stud bolts DIN 976 A2-70 M39x550 mat. A2-70 ( material test required): 80 pcs M52x800 mat. A2-70 ( material test required): 40 pcs. DIN 934 A2-70 M39 mat. A2-70 ( material test required): 160 pcs. M52 mat. A2-70 ( material test required): 80 pcs.