Zinc plated steel No. 12 x 1-1/2 in. self drilling hex washer head screws in Invincibox™. Hex size 5/16 in. Package of 100.
Dottie hex washer head self-drilling screws drill a hole and tap threads in one operation. The drilling operation removes metal and can be used in heavier gauge metals. Length is determined from the base of the fastener head.