Replacing driver screws with brass screws

There is a Audiogon member who replaced all of the steel fasteners on his PBN speakers with brass.  He has them within a Star Sound Energy Room. Tom

Cast copper is used in both sets of speakers in my system page, in fact the paint on my smaller pair was matched to the copper screws!

 My Focus speakers arrived by freight with very loose screws/drivers.  The bass was not right.  I tightened the screws where I thought they were tight, but not overtightened.  No problems with loose drivers or floppy bass since then (I did recheck them after last years home move).   I never had a problem with loose screws on my Signature IIIs.  I moved those locally.  Speakers (as well as other equipment) get jostled quite a bit in freight transport.

"Glupson"
Brass machine screws, "Or any other type",  don't need any info from the manufacturer to give you "any" given specs. The geometry of the part "Screw", does that for you. They are standardized globally at this point. You just need to know the alloy and standard used, "Like S.A.E. for instance", which should be on the packaging even if coded. All with the exception of real oddities are in any machinist handbook. 
Also the studies do call out different alloys of all commonly used materials as applicable. And zinc was one of the metals as well as everything else used today. Standard or forged brass showed no filtering effects. 
Is "Brass" the answer? NO!
Just another piece of the puzzle to play with that we have limited knowledge of and about.
But I keep wondering about the "exact" point at which the "Electrical expression of the waveform coalesces into that waveform. "Which should be instantaneous". And exterior forms of energy affecting the launch. If you can clean the area up as far as stray particles and stabilize the fields a little you could also retard phasing I think. But I think it's beyond the "Classical" physics modeling of field theory and well into....
    I'll be quiet now.......

You know you want to say it...