
| Symbol of grade | C | Si | Mn | P | s | Ni | Cr | Mo |
| STH11 | 0.50 max. | 0.10 to 0.35 | 1.80 max. | 0.035 max. | 0.035 max. | / | / | / |
| STH12 | 0.30 to 0.41 | 0.10 to 0.35 | 1.35 to 1.70 | 0.030 max. | 0.030 max. | / | / | / |
| STH21 | 0.25 to 0.35 | 0.15 to 0.35 | 0.40 to 0.90 | 0.030 max. | 0.030 max. | 0.25 max | 0.80 to 1.2 | 0.15 to 0.3 |
| STH22 | 0.33 to 0.80 | 0.15 to 0.35 | 0.40 to 0.90 | 0.030 max. | 0.030 max. | 0.25 max | 0.80 to 1.2 | 0.15 to 0.3 |
| STH31 | 0.35 to 0.40 | 0.10 to 0.50 | 1.20 to 1.50 | 0.030 max. | 0.030 max. | 0.50 to 1.00 | 0.30 to 0.60 | 0.15 to 0.25 |