Specifications include, but are not limited to: a. Material. Use steel posts that meet Grade 55 hot rolled carbon sheet steel, structural quality, ASTM designation A1011. b. Shape. Use a square tube post formed of 12 gauge (0.105 U.S.S gauge) and 10 gauge (0.135 U.S.S gauge) steel, carefully rolled to size and is welded directly in the corner by high frequency resistance welding and externally scarfed to agree with corner radii. c. Finish. Provide sign posts manufactured from hot-dipped galvanized steel according to ASTM A 653, with a G90 coating. Zinc coat the corner weld after scarfing. Coat the steel with a chromate conversion coating and a clear organic polymer topcoat. Galvanize both the interior and the exterior of the post.
