I'm concerned about using different metals together. I've seen Fiats self destruct because iron waterpumps were installed on aluminium engine blocks and I've heard of the historically notorious freezing of the (iron cannon)balls off the(brass)monkey which (you guessed it) brings us to the subject of lens flanges and the screws used to attach them to the lens board. My SOP is to use brass screws when mounting brass flanges and steel screws when mounting steel flanges but I just received an aluminium flange that fits a compound shutter, so the question is(since I can't find any aluminium wood screws) is whats best to use on aluminium, steel or brass? Or, am I overly concerned about the whole thing and it really dosen't matter as long as the screws are strong enough to keep the lens from falling off??

Thanks!