alloy-steelSAE J429
SAE J429 Grade 8
Alloy steel inch fastener. Head marked with 6 radial lines.
Tensile Rm1034 MPa
Yield Rp0.2896 MPa
HardnessHRC 33–40
Nut class—
Mechanical properties
- Property class
- SAE J429 Grade 8
- Defined in
- SAE J429
- Tensile strength Rm (min)
- 1034 MPa
- Yield strength Rp0.2 (min)
- 896 MPa
- Hardness
- HRC 33–40
- Matching nut class
- —
- Material
- Alloy Steel
Where this grade is used
Property classes are stamped on the head of bolts and screws above 5 mm diameter. A SAE J429 Grade 8 fastener is specified where the joint needs a proof load of roughly 806 MPa or less. Always match the bolt class with a nut of class — or higher so the bolt fails before the thread strips.