Property class 8.8
The everyday structural bolt: 800 MPa tensile, 640 MPa yield (nominal). Minimums rise above 16 mm diameter.
All values
Strength
Yield strength ReH
Upper yield strength guaranteed by the product standard (minimum).
| Condition | Value | Evidence |
|---|---|---|
| ≥ 640MPa | Single source | |
| ≥ 660MPa | Single source |
Tensile strength Rm
Ultimate tensile strength. Product standards give a range or a minimum.
| Condition | Value | Evidence |
|---|---|---|
| ≥ 800MPa | Single source | |
| ≥ 830MPa | Single source |
Ductility
Elongation after fracture A
Minimum elongation; depends on gauge length and test direction.
| Condition | Value | Evidence |
|---|---|---|
| ≥ 12% | Corroborated |
Design values (Eurocode)
Design yield strength fy
Nominal value used in design calculations (before partial factors).
| Condition | Value | Evidence |
|---|---|---|
| 640MPa | Single source |
Design ultimate strength fu
Nominal ultimate strength used in design calculations.
| Condition | Value | Evidence |
|---|---|---|
| 800MPa | Single source |
Property class 8.8 in other standards
Full comparison“Equivalent” tables online usually match grades by name. This one compares the values each standard actually guarantees, so a 30 MPa gap in yield is visible before it is in your calculation.
| Grade | Standard | Min. yield at 10 mm | Tensile at 10 mm | Match | What differs |
|---|---|---|---|---|---|
| Property class 8.8 |  ISO 898-1 | ≥ 640MPa1 | ≥ 800MPa1 | — | Reference grade. |
| F3125 Grade A325 |  ASTM F3125/F3125M | ≥ 634MPa2 | ≥ 827MPa2 | Close match | 120 ksi (827 MPa) tensile and 92 ksi (634 MPa) yield, close to 8.8 above 16 mm; inch threads. |
Sources here are public pages that reproduce ISO 898-1. For design and acceptance, the standard edition named in your specification and the inspection certificate (EN 10204 3.1) of the delivered product take precedence.