carbon-steelISO 898-1
Property Class 4.8
Low or medium carbon steel, general purpose. Common in furniture and light assemblies.
Tensile Rm420 MPa
Yield Rp0.2340 MPa
HardnessHRB 67–95
Nut class4
Mechanical properties
- Property class
- Property Class 4.8
- Defined in
- ISO 898-1
- Tensile strength Rm (min)
- 420 MPa
- Yield strength Rp0.2 (min)
- 340 MPa
- Hardness
- HRB 67–95
- Matching nut class
- 4
- Material
- Carbon Steel
Where this grade is used
The property class is stamped on the head of bolts and screws of M5 and larger, so a 4.8 bolt is marked 4.8. A Property Class 4.8 fastener is specified where the joint needs a 0.2 % proof strength of about 340 MPa or less. Always pair it with a nut of ISO 898-2 class 4 or higher, so the bolt fails before the thread strips.