49 C.F.R. § A to Part 178
Table 1
[Open-hearth, basic oxygen, or electric steel of uniform quality. The following chemical composition limits are based on ladle analysis:]
| Designation | Chemical composition, percent-ladle analysis | ||
| Grade 11 | Grade 21 2 | Grade 32 4 5 | |
| Carbon | 0.10/0.20 | 0.24 maximum | 0.22 maximum. |
| Manganese | 1.10/1.60 | 0.50/1.00 | 1.25 maximum. |
| Phosphorus, maximum | 0.04 | 0.04 | 0.045.6 |
| Sulfur, maximum | 0.05 | 0.05 | 0.05. |
| Silicon | 0.15/0.30 | 0.30 maximum | |
| Copper, maximum | 0.40 | ||
| Columbium | 0.01/0.04 | ||
| Heat treatment authorized | (3) | (3) | (3). |
| Maximum stress (p.s.i.) | 35,000 | 35,000 | 35,000. |
1 Addition of other elements to obtain alloying effect is not authorized.
2 Ferritic grain size 6 or finer according to ASTM E 112-96 (IBR, see § 171.7 of this subchapter).
3 Any suitable heat treatment in excess of 1,100 °F., except that liquid quenching is not permitted.
4 Other alloying elements may be added and shall be reported.
5 For compositions with a maximum carbon content of 0.15 percent of ladle analysis, the maximum limit for manganese on ladle analysis may be 1.40 percent.
6 Rephosphorized Grade 3 steels containing no more than 0.15 percent phosphorus are permitted if carbon content does not exceed 0.15 percent and manganese does not exceed 1 percent.
Check Analysis Tolerances
[A heat of steel made under any of the above grades, the ladle analysis of which is slightly out of the specified range is acceptable if the check analysis is within the following variations:]
| Element | Limit or maximum specified (percent) | Tolerance (percent) over the maximum limit or under the minimum limit | |
| Under minimum limit | Over maximum limit | ||
| Carbon | To 0.15 inclusive | 0.02 | 0.03 |
| Over 0.15 to 0.40 inclusive | 0.03 | 0.04 | |
| Manganese | To 0.60 inclusive | 0.03 | 0.03 |
| Over 0.60 to 1.15 inclusive | 0.04 | 0.04 | |
| Over 1.15 to 2.50 inclusive | 0.05 | 0.05 | |
| Phosphorus7 | All ranges | 0.01 | |
| Sulfur | All ranges | 0.01 | |
| Silicon | To 0.30 inclusive | 0.02 | 0.03 |
| Over 0.30 to 1.00 inclusive | 0.05 | 0.05 | |
| Copper | To 1.00 inclusive | 0.03 | 0.03 |
| Over 1.00 to 2.00 inclusive | 0.05 | 0.05 | |
| Nickel | To 1.00 inclusive | 0.03 | 0.03 |
| Over 1.00 to 2.00 inclusive | 0.05 | 0.05 | |
| Chromium | To 0.90 inclusive | 0.03 | 0.03 |
| Over 0.90 to 2.10 inclusive | 0.05 | 0.05 | |
| Molybdenum | To 0.20 inclusive | 0.01 | 0.01 |
| Over 0.20 to 0.40 inclusive | 0.02 | 0.02 | |
| Zirconium | All ranges | 0.01 | 0.05 |
| Columbium | To 0.04 inclusive | 0.005 | 0.01 |
| Aluminum | Over 0.10 to 0.20 inclusive | 0.04 | 0.04 |
| Over 0.20 to 0.30 inclusive | 0.05 | 0.05 | |
7 Rephosphorized steels not subject to check analysis for phosphorus.
49 C.F.R. §A to Part 178