Since the springs of a flute have constant pressure on them and they need to have the strength to move your keywork around wouldn`t a harder metal like beryllium copper actually be better than Gold for flute springs? Doesn`t the natural malleability of Gold make it the worst material for springs?

Am I totally off base?

I really don`t think the material of the springs matters. Unless it`s between silver plated or solid silver, then obviously the solid silver would be more responsive and quicker, but i wouldn`t think solid siver and gold would make that much of difference, it`s probably just for looks.

Gold springs have been the industry standard for the higher end pro instruments for a few years now. They tend to provide a lighter, relatively quick & even action which is more comfortable if you play flute for large amounts of time regularly. Some of the instrument makers have been experimenting with & providing other materials for the springs but there isn`t any great outcry for change. I don`t believe that silver is ever used for springs. Not even silver plated.
~Bilbo

I mainly agree with you Pico.

I think from my studies in mechanical engineering, that any more standard spring material would perform just as well, providing the length and diameter are of appropriate design for the material, and the cradles are designed for minimum friction.

However...

If a spring is too thick for its length, then there will be a large increase in force needed from the player`s finger DURING the travel of the key. The player interprets this as a sluggish action.

It so happens that this increase is kept to a minimum for any given spring, if the spring operates near its elastic limit. This is usually the case for gold springs.

However, IMHO gold (and other non-traditional spring materials in the engineering trade) is nowhere near the best material, because ideally, to keep this force increase to a minimum during travel, the spring needs to be operating with as much displacement as possible form its rest position. This is certainly not the case with gold springs, which have a very low elastic limit.

The ideal would be a spring such as you suggest, but thin enough and with enough pre-tension, to be both operating with a large displacement and close to its elastic limit.

The problem with such springs (like the blued-steel needle springs of the past, is that to get this large displacement, the spring in its rest position will easily puncture pads while the keys are being mounted.

I still think it is almost certain, that even a quality stainless steel spring, of appropriate diameter and length will function a lot better than gold, or at least match it. Such springs are being sold by Kraus. Unfortunately, if holes are drilled in posts for gold springs, they will be too large for a suitable stainless steel replacement.

Until I am convinced otherwise by a mechanical design engineer, with special knowledge &/or experience with springs, I will continue to believe that the use of precious metals for flute springs is born from silversmithing tradition (with precious little engineering nous) and/or simple snobbery.

Note that steel springs are the norm for oboes, where the `light-touch` demands of the very delicate mechanism are far greater than for a flute.

Gold is better than steel in that it does not corrode. However top quality stainless steel spring material is now available. It never corrodes, and it never breaks.

IMHO

Actually, nickel-titanium, or `Liquidmetal` (trade mark) would possibly be the BEST alloys.