I believe the real question here is how does one size a spring, as opposed to letting the program automatically size it. If this is the case, I suggest reading the CAESAR literature for the spring sizing methodology.

If that is not the case, Mr. Klein is correct. Vendors use specific spring rates for their products. Its a good idea to know the vendor who will provide the springs, so the correct database within CAESAR may be used. Otherwise, make sure the "or equal" clause is in the purchase order.