ASTM A182 – Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service Grade: F12 Class1 and Class2  Chemical Requirements   max,% Elements F12 Class1 F12 Class2 Carbon 0.05-0.15 0.10-0.20 Manganese 0.30-0.60 0.30-0.60 Phosphorus 0.045 0.040 Sulfur 0.045 0.040 Silicon 0.50 0.10-0.60 Chromium 0.80-1.25 0.80-1.25 Molybdenum 0.44-0.65 0.44-0.65   Tensile…