Spring Index

Written by Jerry Ratzlaff on . Posted in Fastener

spring compression 6Spring index, abbreviated as C, is the ratio between the spring and wire diameter for a helical spring.  A higher spring index has a smaller wire and a larger spring diameter.  A lower spring index has a larger wire and a smaller spring diameter.  The spring index tells how tight a spring's coils are.

Spring Index Formula

\(\large{ C = \frac{ D }{ d }  }\)


\(\large{ C }\) = spring index

\(\large{ D }\) = spring diameter

\(\large{ d }\) = wire diameter


Tags: Equations for Spring