hey guys. i have searched but i dont really understand the differance between say 12k and like 500lb spring rates. whats the differance. why do some companies advertise 12k and others 500lb. is their like a conversion formula so when im shoppin around i know who has the best spring rates.

 

12K is short for 12 kg/mm, the metric way to measure spring rate. Multiply kg/mm by 56 to get the spring rate in lb/in. 12 kg/mm is damn stiff, as it is around 675 lb/in springs.