Which platinum alloy should I use for hand fabrication of wedding
bands andother jewelry pieces?
While other alloys have various properties that may be good, overall
10 percent iridium is the most traditionally used for hand
fabrication, for it's overall combination of hardness, weldability,
and more. Ruthenium is sometimes used, primarily because it's a
little cheaper, and may cast better.
The one class of alloys worth looking at which you don't mention,
though, are the platinum alloys that can be heat treated. These can
be fabricated like the others, though sometimes not as easily.
However, after fabrication, they can be heat treated to higher levels
of hardness than normally possible, and if you're looking for higher
strength and rigidity, these alloys deserve your attention.
They are proprietary, so ingredients aren't so easily listed.
Discuss this with your metals supplier. As to the alloy being prone
to scratching, well, don't expect miracles. Any platinum alloy will
be prone to scratches, even the heat treatable ones, though those to
a lesser degree. You should use platinum simply with the expectation
that this will occur over time.