| Standard reference | Material | Hardness range |
| NFE 25-511 | spring steel | HV 420÷510 |
| NFE 25-511 | stainless steel | HV 160 min |
| SPERRKANT | spring steel | HV 420÷510 |
| SPERRKANT | tainless steel | HV 160 min |
| DIN 6796 | spring steel | HV 420÷490 |
| DIN 6908 | spring steel | HV 420÷490 |
| UNI 8836 | spring steel | HV 400÷470 |
| UNI 8837 | spring steel | HV 400÷470 |
| UNI 8838 | spring steel | HV 400÷470 |
| DIN 6904 | spring steel | HV 430÷530 |
| DIN 137A | spring steel | HV 430÷530 |
| DIN 137B | spring steel | HV 430÷530 |
Technical sheet