Class 1 - Steel pipe Grade A- ASTM F1083, hot-dipped galvanized schedule 40 pipe Wheatland Tube Co. is a prime U.S. manufacturer Grade B- ASTM F1043 Group IC, Wheatland WT-40 Class 2 - Aluminum alloy schedule 40 pipe Class 3 – ASTM F1043 Group II Formed steel “C” sections Class 4 – Steel H-sections (no longer available)