Grade 8.8, metric grading, DIN 933/931 medium carbon steel, heat treated with strength class stamped on the head (similar in strength to grade 5 ).  Mimimum tensile strength is 120,000 psi, up to 16 mm and 120,000 greater than 16 mm.

Also meets ANSI and ASTM specs for metric 8.8 requirements.

Standard plain finish unless otherwise indicated.