Because of their own hardness and density, rhodium, iridium, ruthenium and osmium alloy with platinum and palladium to produce metals which combine the best qualities of each with a unique hardness and durability.

PGMs can have a quite remarkable effect on other metals. For example, titanium's corrosion resistance is boosted a hundred times by the addition of just 0.1% of ruthenium. This gives titanium an even more effective and durable role in aerospace and marine applications where resistance to extremes of temperature and salt water is crucial.

Application for alloys between the PGMs include fuel cells, industrial crucibles and tools, and jewellery.