Precious Metal Pt90Rh10
ASTM E230 Type S · EN PtRh10
Pt90Rh10 is a platinum–10 % rhodium solid-solution alloy, standardised in ASTM E230 as the positive leg of the Type S thermocouple paired with pure platinum.
Reference datasheet — Pt90Rh10 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the Annealed condition
Pt90Rh10 tempers and conditions
Pt90Rh10 is supplied in 6 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
induction-melted crucibles, bushings, labware | Use for melt-formed vessels and thick shapes; coarse grain gives lower strength and worse high-temperature creep than wrought/ZGS material. | 150 | 280 | 25 | 83 HB | 8.9 % IACS |
AnnealedDefault soft, fully recrystallized wire/sheet (thermocouple grade) | Standard stocked condition for S-type thermocouple wire and lab foil: maximum ductility and stable, calibration-conforming EMF. | 170 | 320 | 35 | 88 HB | 9.1 % IACS |
Type S thermocouple wire, IEC 60584-1 Class 1 / ASTM E230 special limits | Annealed, EMF-calibrated wire pairs supplied with certificate when tolerance of ±1 °C / ±0.25 % is required for reference thermometry. | 170 | 320 | 35 | 88 HB | 9.1 % IACS |
ZGS / DPH oxide-dispersion-strengthened PtRh10 | Zirconia-grain-stabilized version for glass-fibre bushings and high-temperature vessels needing greatly improved creep life and grain stability above 1200 °C. | 220 | 350 | 20 | 107 HB | 9 % IACS |
Half hard | Choose when the wire or strip must hold its shape (formed leads, spring contacts) yet still take a bend. | 400 | 500 | 10 | 152 HB | 8.9 % IACS |
Hard drawn | Highest room-temperature strength/stiffness for fine wire handling, springs and electrodes; anneal (or first heat cycle) before use as a calibrated thermocouple. | 620 | 720 | 3 | 19 HRC | 8.8 % IACS |
Supply forms, finishes and certifications
Ways Pt90Rh10 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
Foil-CR | Cold rolled foil/strip | Supply form |
What is Pt90Rh10?
Pt90Rh10 is a platinum–10 % rhodium solid-solution alloy, standardised in ASTM E230 as the positive leg of the Type S thermocouple paired with pure platinum. It is chosen for reference-grade high-temperature measurement to about 1450 °C and is supplied as annealed, half-hard and hard-drawn wire, cold-rolled foil, Class 1 thermocouple wire and ZGS oxide-dispersion-strengthened stock. Annealed values are 170 MPa yield, 320 MPa tensile, 35 % elongation, 88 HB and 9.1 % IACS. Machinability is very low (22), metal cost is high, and contact with silica, graphite or reducing atmospheres causes embrittlement and EMF drift; Pt87Rh13 (Type R) gives higher EMF output. Pt90Rh10 has a density of 19.97 g/cm³ (0.721 lb/in³), heavier than 92% of precious metal grades. It melts at 1,850°C (3,362 °F). Pt90Rh10 has a yield strength of 170 MPa (24.7 ksi) and a tensile strength of 320 MPa (46.4 ksi) — weaker than 64% of precious metal grades. Elongation at break is 35% and the elastic modulus is 193 GPa (28 Msi).
What is Pt90Rh10 used for?
- Type S thermocouples
- High-temperature furnace sensors
- Reference thermometry
Advantages
- High service temperature — 1,450°C (2,642 °F), better than 99% of precious metal grades
- Stiff — 193 GPa (28 Msi), better than 95% of precious metal grades
- Good corrosion resistance — 99/100, better than 93% of precious metal grades
- Ductile — tolerates forming and impact — 35%, better than 83% of precious metal grades
- Readily welded — 75/100, better than 78% of precious metal grades
Limitations
- Difficult to machine — 22/100, worse than 98% of precious metal grades
- Poor heat conductor — 30 W/m·K (17.3 BTU/hr·ft·°F), worse than 94% of precious metal grades
- Heavy — 19.97 g/cm³ (0.721 lb/in³), worse than 92% of precious metal grades
- High embodied carbon — 14,000 kg CO₂/kg, worse than 88% of precious metal grades
- Low electrical conductivity — 9.1 % IACS, worse than 82% of precious metal grades
Pt90Rh10 properties
Typical room-temperature values for Pt90Rh10-Annealed; bars are the position among precious metal grades.
Physical3
Pt90Rh10 has a density of 19.97 g/cm³ (0.721 lb/in³), heavier than 92% of precious metal grades. It melts at 1,850°C (3,362 °F).
Mechanical10
Pt90Rh10 has a yield strength of 170 MPa (24.7 ksi) and a tensile strength of 320 MPa (46.4 ksi) — weaker than 64% of precious metal grades. Elongation at break is 35% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
Pt90Rh10 is rated for continuous service to 1,450°C (2,642 °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 9 µm/m·K (5 µin/in·°F).
Electrical3
Pt90Rh10 conducts electricity at 9.1 % IACS, worse than 82% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (99/100), better than 93% of precious metal grades.
Sustainability3
Producing a kilogram of Pt90Rh10 takes about 200,000 MJ of energy and emits 14,000 kg of CO₂ — more than 85% of precious metal grades. Typical recycled content is 50%.
Manufacturability8
Pt90Rh10's machinability is poor (22/100, worse than 98% of precious metal grades); weldability very good (75/100); formability excellent (92/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the precious metal family
Yield strength against density for every precious metal grade FabDigit runs. Pt90Rh10 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Pt90Rh10
Is Pt90Rh10 easy to machine?
Very gummy and expensive — use sharp carbide/diamond tools, light DOC, flood coolant, and capture every chip for refining; wherever possible form from wire/foil instead of cutting.
Can Pt90Rh10 be welded?
Junctions are made by resistance, microplasma, laser or oxy-hydrogen fusion welding without flux; keep the joint free of Si, Fe and Pb contamination to avoid embrittlement and EMF drift.
Can Pt90Rh10 be formed, bent or molded?
Excellent cold formability in the annealed state (drawn below 0.05 mm, rolled to foil); interstage anneal at 900–1100 °C in air, and re-anneal thermocouple wire before calibration.
Pt90Rh10 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 |
|---|---|---|
| RhIEC 60584 / ASTM E1159 Type SP leg | 9.5 – 10.5 | 10 |
| Pdtypical impurity limit, thermocouple grade | ≤ 0 | |
| Irtypical impurity limit | ≤ 0 | |
| Fetypical impurity limit | ≤ 0 | |
| Siembrittling impurity, tightly limited | ≤ 0 | |
| PtPt + Rh ≥ 99.99 % for thermocouple grade | balance |
What surface finishes work on Pt90Rh10?
No coating needed or possible — clean chemically (hot HCl/dilute nitric plus rinsing) or by flame; polish to mirror finish and avoid contact with graphite, silica-rich supports and reducing furnace atmospheres.
Equivalent designations
Standards and trade names that resolve to Precious Metal Pt90Rh10 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- E230 Type S
- EN / DIN / Werkstoff-Nr.
- PtRh10
How much does Pt90Rh10 cost?
Pt90Rh10 is a high-cost precious metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Pt90Rh10 — frequently asked
What is Pt90Rh10 used for?
Pt90Rh10 is typically used for type S thermocouples, high-temperature furnace sensors and reference thermometry. In short: reference-grade Type S leg; stable to 1450 °C; excellent cold formability (92).
What is the yield strength of Pt90Rh10?
Pt90Rh10 has a typical yield strength of 170 MPa (24.7 ksi) and a tensile strength of 320 MPa (46.4 ksi) — weaker than 64% of precious metal grades. Strength varies by condition: see the 6 listed tempers.
Is Pt90Rh10 easy to machine?
Not especially — machinability is rated poor (22/100, worse than 98% of precious metal grades). Very gummy and expensive — use sharp carbide/diamond tools, light DOC, flood coolant, and capture every chip for refining; wherever possible form from wire/foil instead of cutting.
Can Pt90Rh10 be welded?
Yes — weldability is rated very good (75/100). Junctions are made by resistance, microplasma, laser or oxy-hydrogen fusion welding without flux; keep the joint free of Si, Fe and Pb contamination to avoid embrittlement and EMF drift.
What surface finishes work on Pt90Rh10?
No coating needed or possible — clean chemically (hot HCl/dilute nitric plus rinsing) or by flame; polish to mirror finish and avoid contact with graphite, silica-rich supports and reducing furnace atmospheres.
Can Pt90Rh10 be formed, bent or molded?
Excellent cold formability in the annealed state (drawn below 0.05 mm, rolled to foil); interstage anneal at 900–1100 °C in air, and re-anneal thermocouple wire before calibration.
What is the maximum service temperature of Pt90Rh10?
Pt90Rh10 is rated for continuous use to about 1,450°C (2,642 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Pt90Rh10 Annealed and Pt90Rh10 H-Drawn?
Annealed is the default condition — standard stocked condition for S-type thermocouple wire and lab foil: maximum ductility and stable, calibration-conforming EMF. H-Drawn: highest room-temperature strength/stiffness for fine wire handling, springs and electrodes; anneal (or first heat cycle) before use as a calibrated thermocouple. Yield strength is 170 MPa in Annealed versus 620 MPa in H-Drawn.
How much does Pt90Rh10 cost?
Pt90Rh10 is a high-cost precious metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM E1159 — Specification for Thermocouple Materials, Platinum-Rhodium Alloys and Platinum — ASTM (2018)
- ASTM E230/E230M — Standard Specification and Temperature-EMF Tables for Standardized Thermocouples — ASTM (2017)
- IEC 60584-1 Thermocouples — Part 1: EMF specifications and tolerances — IEC (2013)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (precious metals) — ASM International (1990)
- Platinum-rhodium alloy and ZGS PtRh thermophysical data — Johnson Matthey / Heraeus (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.