rixthetrick,
By now I figured out that you think I am just attempting to annoy here.
Discussion about brass vs. iron is meaningless without considering many other variables that are sticking out asking for consideration before one even buys the first brass screw. Without them, whole discussion seems like "my way or no way".
In my example above, the amount of brass delegated to each speaker would double. If brass actually makes a difference, in any semi-reasonable approach that might impact the result. Unless one decides that preliminary result is what one desires it to be.
I will not disassemble my speakers for something like this. Neither I have enough time or interest in proving or disproving slightly dubious claims from people who dismiss any deeper, and potentially more complicated and sophisticated way of approaching technical issues. I will leave disassembly to those more inclined to fine manual work and keep myself actually contributing to their research with ideas they somehow did not think of.
I do not know what wood I would use for screws. In fact, my first question was if different wood would make a difference.
What made me think of wood was very simple. Many, if not most, of the speakers are made of some iteration of wood. In other things, problem is frequently at the spot where two different media meet. Decreasing difference in physical properties of adjoining media might be beneficial, or even detrimental, to desired outcome.
From that, it came to "wouldn’t carefully choosing the screw material in reference to the enclosure material be more beneficial than just a blank statement....brass is better".
You see, it is not that imaginative. It is very simple reasoning.
When it comes to imperial vs. metric thread, that is the next level of designing the research. It might be a good consideration, but we are still in the beginning stages of it.