Spring Rates for Compression Springs

Compression Spring Design Resources – What Is Spring Rate & How to Determine Spring Rate?

Spring rate is the change in load per unit of deflection and may be determined using the following procedure:

  1. Deflect* the spring approximated 20% of the available deflection and measure the load (P1) and the height (L1).
  2. Deflect* the spring approximately 80% of the available deflection and measure the load (P2) and the height (P2).
  3. Calculate the rate (lbs/inch) or (N/mm) by using the following formula:

R=

(P2 - P1)

(L1 - L2)

*To deflect a spring one would apply or remove an external load, causing the spring ends/arms to move. Please contact the Newcomb Spring facility nearest you for more information on spring rate and other considerations of spring design.