Precious Metal 90Pt-10Ir-H (Hardened)
Heat-treated state
Choose for spring contacts, probe needles and wear surfaces where maximum hardness and elastic stiffness matter more than formability.
Values for the H condition
Other 90Pt-10Ir tempers and conditions
90Pt-10Ir is listed in 3 conditions; see the grade overview at 90Pt-10Ir.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ANNDefault Annealed | Default stock condition for wire, strip and contact rivets that must be drawn, coined, bent or welded before use. | 205 | 415 | 28 | 125 HB | 7 % IACS |
Half hard | Compromise condition for contact springs and slip-ring wire needing stiffness while retaining some bending ductility. | 480 | 620 | 8 | 190 HV | 6.9 % IACS |
HThis page Hardened | Choose for spring contacts, probe needles and wear surfaces where maximum hardness and elastic stiffness matter more than formability. | 690 | 830 | 2 | 23 HRC | 6.8 % IACS |
What is 90Pt-10Ir-H?
90Pt-10Ir-H is 90Pt-10Ir heat treated to H — choose for spring contacts, probe needles and wear surfaces where maximum hardness and elastic stiffness matter more than formability. 90Pt-10Ir-H has a yield strength of 690 MPa (100 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 100% of precious metal grades. Elongation at break is 2% and the elastic modulus is 195 GPa (28.3 Msi). 90Pt-10Ir-H has a density of 21.55 g/cm³ (0.779 lb/in³), heavier than 99% of precious metal grades. It melts at 1,780°C (3,236 °F). ANN is the default condition FabDigit quotes; H is available on request or by drawing note.
Advantages
- High strength — 690 MPa (100 ksi), better than 100% of precious metal grades
- Good corrosion resistance — 100/100, better than 98% of precious metal grades
- Stiff — 195 GPa (28.3 Msi), better than 96% of precious metal grades
- High service temperature — 600°C (1,112 °F), better than 85% of precious metal grades
Limitations
- Heavy — 21.55 g/cm³ (0.779 lb/in³), worse than 99% of precious metal grades
- Limited ductility — 2%, worse than 98% of precious metal grades
- Limited formability — 25/100, worse than 95% of precious metal grades
- Poor heat conductor — 30 W/m·K (17.3 BTU/hr·ft·°F), worse than 94% of precious metal grades
- Low electrical conductivity — 6.8 % IACS, worse than 90% of precious metal grades
90Pt-10Ir-H properties
Typical room-temperature values for 90Pt-10Ir-H; 17 are specific to this condition. Other listed values are 90Pt-10Ir reference data and may not represent this condition. Bars are the position among precious metal grades.
Physical3
90Pt-10Ir-H has a density of 21.55 g/cm³ (0.779 lb/in³), heavier than 99% of precious metal grades. It melts at 1,780°C (3,236 °F).
Mechanical12
90Pt-10Ir-H has a yield strength of 690 MPa (100 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 100% of precious metal grades. Elongation at break is 2% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
90Pt-10Ir-H is rated for continuous service to 600°C (1,112 °F). It conducts heat at 30 W/m·K (17.3 BTU/hr·ft·°F), worse than 94% of precious metal grades. Thermal expansion is 8.8 µm/m·K (4.89 µin/in·°F).
Electrical3
90Pt-10Ir-H conducts electricity at 6.8 % IACS, worse than 90% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (100/100), better than 98% of precious metal grades.
Sustainability4
Producing a kilogram of 90Pt-10Ir-H takes about 245,000 MJ of energy and emits 13,500 kg of CO₂ — more than 93% of precious metal grades. Typical recycled content is 30%.
Manufacturability8
90Pt-10Ir-H's machinability is fair (45/100, better than 59% of precious metal grades); weldability good (55/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 90Pt-10Ir-H
Is 90Pt-10Ir easy to machine?
Gummy and strongly work-hardening — use sharp carbide or diamond tools, light positive-rake cuts, high speed with copious coolant, and collect all swarf for refining.
Can 90Pt-10Ir be welded?
Excellent for resistance, micro-TIG and laser welding of contacts to Cu/Ni carriers; avoid contamination by Pb/Bi/Si and reducing melts that embrittle PGMs.
Can 90Pt-10Ir be formed, bent or molded?
Anneal at 900–1100 °C in air and cold draw/roll in 30–50 % steps; the 10 % Ir grade takes deeper draws and tighter bends than 85Pt-15Ir before intermediate anneals.
What surface finishes work on 90Pt-10Ir?
Takes a permanent mirror polish with no plating or passivation needed; ultrasonic clean and avoid halide residues on switching surfaces.
90Pt-10Ir chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Irsolid-solution strengthener | 9.5 – 10.5 | 10 |
| Other PGM + impuritiestotal, Rh/Pd/Ru/Fe/Cu traces | ≤ 0.15 | — |
| Pt | ≥ 89.5 (balance) | — |
90Pt-10Ir-H — frequently asked
What is 90Pt-10Ir-H used for?
90Pt-10Ir-H is typically used for precision relay contacts, slip rings and electrode tips. In short: most ductile Pt-Ir grade; stable to 1200 °C; fine-wire drawing grade.
What is the yield strength of 90Pt-10Ir-H?
90Pt-10Ir-H has a typical yield strength of 690 MPa (100 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 100% of precious metal grades. Strength varies by condition: see the 3 listed tempers.
Is 90Pt-10Ir-H easy to machine?
Reasonably — machinability is rated fair (45/100, better than 59% of precious metal grades). Gummy and strongly work-hardening — use sharp carbide or diamond tools, light positive-rake cuts, high speed with copious coolant, and collect all swarf for refining.
Can 90Pt-10Ir-H be welded?
Yes — weldability is rated good (55/100). Excellent for resistance, micro-TIG and laser welding of contacts to Cu/Ni carriers; avoid contamination by Pb/Bi/Si and reducing melts that embrittle PGMs.
What surface finishes work on 90Pt-10Ir-H?
Takes a permanent mirror polish with no plating or passivation needed; ultrasonic clean and avoid halide residues on switching surfaces.
Can 90Pt-10Ir-H be formed, bent or molded?
Anneal at 900–1100 °C in air and cold draw/roll in 30–50 % steps; the 10 % Ir grade takes deeper draws and tighter bends than 85Pt-15Ir before intermediate anneals.
What is the maximum service temperature of 90Pt-10Ir-H?
90Pt-10Ir-H is rated for continuous use to about 600°C (1,112 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 90Pt-10Ir-ANN and 90Pt-10Ir-H?
ANN is the default condition — default stock condition for wire, strip and contact rivets that must be drawn, coined, bent or welded before use. H: choose for spring contacts, probe needles and wear surfaces where maximum hardness and elastic stiffness matter more than formability. Yield strength is 205 MPa in ANN versus 690 MPa in H.
Sources
- ASTM B684 — Platinum-Iridium Electrical Contact Material — ASTM International (2020)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Precious Metals) — ASM International (1990)
- Platinum-Iridium alloy property tables — Johnson Matthey / Heraeus (2022)
- PGM physical and electrical property compilation — International Platinum Group Metals Association (2021)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.