Characteristic values of SK85

keyword: Poisson'sratio; tensilestrength; springmaterial; SK85; longitudinalelasticmodulus; transverseelasticmodulus

Question Spring Newbie 2018/7/19(Thu) 14:55

Please tell me these characteristic values of SK85.
1) Tensile strength
2) Longitudinal elastic modulus
3) Transverse elastic modulus
4) Poisson’s ratio

Answer Tokai Spring 2018/7/19(Thu) 15:48

Thank you for your question!!!
Physical properties of SK85 (SK5) are as follows. (From JIS G4401)

[Cold-rolled steel sheets and strips]
Cold-rolled steel’s hardness: (Hv200~290)
Annealing hardness: Hv200 or less ⇒ 620 MPa or less (converted value)

[Hot-rolled steel sheets and strips]
Hot-rolled steel’s hardness: HRC43 or less ⇒ 860 MPa or less (converted value)
Annealing hardness: HRB100 or less ⇒ 805 MPa or less (converted value).

However, during quenching and tempering, the hardness may be adjusted according to the application and product shape to aim for HRC43 or higher.

The elastic modulus will be the general value for similar steel materials.
Longitudinal elastic modulus: 206000
Transverse elastic modulus: 78500
Poisson’s ratio: 0.3