bolt steel Material Chemical Composition
| Element | B7 (AISI 4140) | B8 (AISI 304) | B8M (AISI 316) | B16 (AISI 4140) |
| Carbon | 0.37 - 0.49% | 0.08% max | 0.08% max | 0.37 - 0.49% |
| Manganese | 0.65 - 1.10% | 2.00% max | 2.00% max | 0.65 - 1.10% |
| Phosphorus, max | 0.04% | 0.05% | 0.05% | 0.04% |
| Sulfur, max | 0.04% | 0.03% | 0.03% | 0.04% |
| Silicon | 0.15 - 0.35% | 1.00% max | 1.00% max | 0.15 - 0.35% |
| Chromium | 0.75 - 1.20% | 18.0 - 20.0% | 16.0 - 18.0% | 0.75 - 1.20% |
| Nickel | 8.0 - 11.0% | 10.0 - 14.0% | ||
| Molybdenum | 0.15 - 0.25% | 2.00 - 3.00% | 0.15 - 0.25% |
