Engineering Tools
Reference data for specifying and sourcing fasteners correctly — the numbers a procurement or design engineer actually needs.
Mechanical properties by grade
Tensile strength, proof stress and typical hardness range per property class (ISO 898-1 / ISO 3506-1).
| Grade | Tensile strength | Proof stress | Hardness range |
|---|---|---|---|
| 4.6 | 400 MPa | 225 MPa | 114–238 HB |
| 4.8 | 420 MPa | 310 MPa | 124–238 HB |
| 5.6 | 500 MPa | 280 MPa | 147–238 HB |
| 5.8 | 520 MPa | 380 MPa | 152–238 HB |
| 8.8 | 800 MPa | 600 MPa | 22–32 HRC |
| 10.9 | 1040 MPa | 830 MPa | 32–39 HRC |
| 12.9 | 1220 MPa | 970 MPa | 39–44 HRC |
| A2/A4-70 | 700 MPa | 450 MPa | max 220 HB |
| A2/A4-80 | 800 MPa | 600 MPa | max 250 HB |