08-01-2007, 04:38 PM
Join Date: Oct 2003
Location: Westminster, CO
What I Drive: 99 miata, 05Mazda6, 09GTI, 12Imprez
FF Reputation: 141
Buy-Sell-Trade Rating: (0
Spring rate equivalence
Springs come rated in pounds per inch or in kilograms per milimeter. In essence, this is the amount of weight needed to compress the spring one inch or one mm. Naturally the more weight it takes the stiffer the spring is.
To convert a spring that is measured in kilograms per milimeter, simply mutiply by 55.99745 to get lbs per inch.
Example a spring is rated at 2.2 kg/mm
2.2 x 55.99745 = 123.194 lbs/in
This may help should you purchase springs from overseas where most measurements are in kg/mm.