alloy-steelISO 898-1
Property Class 10.9
High strength alloy steel. Used in automotive suspension and structural joints.
Tensile Rm1040 MPa
Yield Rp0.2940 MPa
HardnessHRC 32–39
Nut class10
Mechanical properties
- Property class
- Property Class 10.9
- Defined in
- ISO 898-1
- Tensile strength Rm (min)
- 1040 MPa
- Yield strength Rp0.2 (min)
- 940 MPa
- Hardness
- HRC 32–39
- Matching nut class
- 10
- Material
- Alloy Steel
Where this grade is used
Property classes are stamped on the head of bolts and screws above 5 mm diameter. A Property Class 10.9 fastener is specified where the joint needs a proof load of roughly 846 MPa or less. Always match the bolt class with a nut of class 10 or higher so the bolt fails before the thread strips.