You’ll also benefit from quick

Hardness for plain and zinc plated washers is HRC 38-45 and HRC 26-45 for hot-dip galvanized washers per ASTM F436

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

and the jaws open to a lock position when the screw is inserted

For heavy gauge sheet metal

#21 Heavy Duty Jobber Drill Bit (12) 9/16-12 Grade 8 Hex Cap Screws Yellow Zinc Plated You’ll also benefit from quick#21 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.