[kenchan]

also note that these are progressive rate springs...meaning, they have
initial and full compression rates and many variable rates in between.

those numbers are to be used only as a guide... there is no indication
whether those are initial or full or just averages.

if you see a rate like 500lbs, you know they are very stiff.

if you see 2 different rates from the same manufactuer then
you can tell which are stiffer as they probably (assuming)
used the same measuring method(s).

2 different rates from 2 different manufacturers.... you can only
guess.