How to Determine What Platinum Alloy to Use

How to Determine What Platinum Alloy to Use

Different Platinum Alloys

This chart will tell you which alloy is best suited for your job.

90/10 Pt/Ir Satisfactory Excellent Excellent Poor
95/5 Pt/Ir Poor Excellent Excellent Poor
Pt 950/Co Excellent Good Good Good
Pt 950/Ru Good Excellent Good Excellent
Pt 950/Heat Treatable Excellent Good Excellent Excellent


90/10 Iridium 110 HV 55,000 PSI
95/5 Iridium 80 HV 40,000 PSI
Platinum / Cobalt 135 HV 64,000 PSI
Platinum / Ruthenium 135 HV 66,000 PSI
Pt 950/Heat Treatable 240 - 330 HV Variable 100,000 PSI +

90 / 10 Pt/Ir is an all round pt alloy. It can be used for all applications, but is best suited for fabrication.

95 / 5 PT/Ir is a fabrication alloy. It has high malleability and work-hardens rapidly. It is great for die striking. Because of its low hardness, it is not well suited for casting.

Pt 950 / Cobalt has a very fine grain and is ideal for casting. It is slightly Ferro-magnetic and oxidizes at about 1000C. The oxidation can be removed with hot Sparex.

PT 950 / Ruthenium is the best choice for multi-purpose use. It is ideal for machining and fabrication. Casting will deliver good results. Because of its structure, fine detail castings are somewhat more difficult to achieve.

Pt 950 heat treatable alloys are ideal when spring action is needed or a harder product is desired. The hardening feature gives these alloys great flexibility. The properties vary with alloys from different vendors. Ask for data sheets from metal providers.


Source: Platinum Guild International USA

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