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% |