ASTM A320 Chemical Properties

 

 

 

 

Element L7 (AISI 4140) L43 (AISI 4340) B8 (AISI 304) B8M (AISI 316)
Carbon 0.38 - 0.48% 0.38 - 0.43% 0.08% max 0.08% max
Manganese 0.75 - 1.00% 0.75 - 1.00% 2.00% max 2.00% max
Phosphorus, max 0.035% 0.035% 0.045% 0.045%
Sulfur, max 0.040% 0.040% 0.030% 0.030%
Silicon 0.15 - 0.35% 0.15 - 0.35% 1.00% max 1.00% max
Chromium 0.80 - 1.10% 0.70 - 0.90% 18.0 - 20.0% 16.0 - 18.0%
Nickel 1.65 - 2.00% 8.0 - 11.0% 10.0 - 14.0%
Molybdenum 0.15 - 0.25% 0.20 - 0.30% 2.00 - 3.00%