Tapco offers Grade 5 No.1 Norway Flat Countersunk Head elevator bolts. The Grade 5 elevator bolts have greater proof load, minimum yield strength and minimum tensile strength than Grade 1 or Grade 2 bolts, according to the company. Bolts feature a yellow zinc-plated (CR3) coating and SAE grade marking. They are available in 14 sizes ranging from ¼-20-by-3/4 inches to 3/8-16-by-2 inches.