Chemical Composition
| Designation of garde | Chemical Composition | ||||
| C | Si | Mn | P | S | |
| STKR 400 | 0.25 max. | - | - | 0.040 max. | 0.040 max. |
| STKR 490 | 0.18 max. | 0.55 max. | 1.50 max. | 0.040 max. | 0.040 max. |
Mechanical Properties
| Designation of garde | |||
| Tensile strength N/mm²｛kgf/mm²｝ | Yield point or proof stress N/mm²｛kgf/mm²｝ | Elongation % (No.5 test piece) | |
| STKR 400 | 400｛41｝min. | 245｛25｝min. | 23 min. |
| STKR 490 | 490｛50｝min. | 325｛33｝min. | 23 min. |