This is my first time posting a question here.
I’m trying to design a thin flat spring using SK5 material, but I don’t know enough about the strength of SK5.
Could you tell me the strength of SK5 (yield point (proof stress?), tensile strength, bending strength, bending fatigue limit, etc.)?
Thank you for writing to us, Paru!
In terms of strength, when a spring is heat-treated after forming, the tensile strength is determined by the hardness after the heat treatment.
If the hardness is HRC42 to 48, the tensile strength will be 1340 to 1635 N/mm^2. By the way, the allowable bending stress is about 75% of the tensile strength. (It is recommended to set the hardness within the range of HRC40 to 50).
Also, tensile strength is often used for design.
Regarding bending fatigue limit, we will send you the reference materials later! Thanks again for your question!
Thank you for your reply. I need to ask you another question. Is the SK5’s yield point not often used in the design?
Hello Paru! The SK5’s yield point is not used in the spring design.
Generally, spring designs use the lower end of the material’s tensile strength range.
Thank you!
