Hardness is Rockwell C32 maximum and proof load is 72

and ASTM F606 1990

3/4-10 x 4 1/2 Grade 8 Hex Cap Screw Yellow Zinc Plated

Galvanized nuts are over tapped per ASTM A563

#36 Heavy Duty Jobber Drill Bit (12) M20-2.50 Hex Cap Screws DIN 933 18-8 Stainless Steel (A2) Hardness is Rockwell C32 maximum#36 Heavy Duty Jobber Drill Bit . Web construction is heavier than general purpose construction making it particularly suitable for cotter pin hole drilling and cross hole drilling in head of bolts. The heavy construction affords efficient drilling in stainless steel and other hard materials. The split point reduces the thrust requirements and minimizes walking.