Not anywhere near all the way tight, plant corn into worked ground and beans notill with coulters. This is with the single closing wheels with 2 springs/wheel.

I would say that if I pull up on the wheel a couple inches there is about 50-75 lbs of down pressure. With those springs all the way tight you probably have over 200 lbs of down pressure.

Those same springs are used for the heavy duty down pressure springs on the parallel arms, according to the book they are capable of something like 110 lbs/spring when used on the parallel arms.