I am a beginner in spring design.
We are currently designing thin flat springs. The shape is like a straight flat component with an R-shaped part. Could you tell me the following information?
1. Young’s modulus of SUS301-CSP, SUS304-CSP, and phosphor bronze
2. Which value should be considered as the allowable stress value at the time of design, yield strength, spring limit value, or 75% of tensile strength?
I’m sorry for the rudimentary question but thank you in advance for your reply.
Thank you for writing to us, Mr. Bane!
1. Young’s modulus of SUS301-CSP and SUS304-CSP: 186000N/mm^2; Young’s modulus of phosphor bronze: 98000N/mm^2
2. Which value should be considered as the allowable stress value at the time of design, yield strength, spring limit value, or 75% of tensile strength?
→ SUS301-CSP and SUS304-CSP: 75% of tensile strength
Phosphor bronze: Spring limit
3. Definition of springs’ sag (permanent deformation)
→ The amount of decrease of the free length of the springs when the load is removed compared to the free length before the load is applied to the springs.
* SUS304（EQ to S30400 by ASTM, X5CrNi1810 by DIN, L-No6X5CrNi 18-9 by ISO ）
