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Precious Metal Pt950 Stress Relieved

Heat-treated state

Use a low-temperature stress relief after cold work or welding to remove internal stress while keeping part of the cold-work strength, preventing cracked settings or dimensional drift.

Specialty cost $$$$$

Values for the Stress Relieved condition

Other Pt950 tempers and conditions

Pt950 is listed in 4 conditions; see the grade overview at Pt950.

Compare all 4 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
ODefault
Annealed
Pick the annealed, recrystallized temper as standard stock for sheet, strip, wire and tube: 35 % elongation suits stamping, drawing, stone setting and further cold forming, at the lowest strength.13031035105 HB—
investment / centrifugal cast, no post heat treatment
Use as-cast investment or centrifugal castings for complex small jewellery parts; coarse grain and some shrinkage porosity hold tensile strength to 350 MPa, below wrought material.17535022124 HB7 % IACS
Stress RelievedThis page
low-temperature stress relief after cold work or welding
Use a low-temperature stress relief after cold work or welding to remove internal stress while keeping part of the cold-work strength, preventing cracked settings or dimensional drift.25040020142 HB7 % IACS
hard temper (approx. 40–60 % reduction)
Choose the hard temper from roughly 40–60 % cold reduction for spring wire, prongs, electrode wire and fine tubing needing 560 MPa yield and wear resistance; elongation falls to 3 %.5606503235 HB—

What is Pt950 Stress Relieved?

Pt950 Stress Relieved is Pt950 heat treated to Stress Relieved — use a low-temperature stress relief after cold work or welding to remove internal stress while keeping part of the cold-work strength, preventing cracked settings or dimensional drift. Pt950 Stress Relieved has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 400 MPa (58 ksi) — stronger than 81% of precious metal grades. Elongation at break is 20% and the elastic modulus is 172 GPa (24.9 Msi). Pt950 Stress Relieved has a density of 20.1 g/cm³ (0.726 lb/in³), heavier than 94% of precious metal grades. It melts at 1,755°C (3,191 °F). O is the default condition FabDigit quotes; Stress Relieved is available on request or by drawing note.

Advantages

  • Good corrosion resistance — 100/100, better than 98% of precious metal grades
  • Stiff — 172 GPa (24.9 Msi), better than 90% of precious metal grades
  • Readily welded — 80/100, better than 87% of precious metal grades
  • Polishes to a fine finish — 95/100, better than 86% of precious metal grades
  • High service temperature — 600°C (1,112 °F), better than 85% of precious metal grades

Limitations

  • High embodied carbon — 16,000 kg CO₂/kg, worse than 96% of precious metal grades
  • Heavy — 20.1 g/cm³ (0.726 lb/in³), worse than 94% of precious metal grades
  • Low electrical conductivity — 7 % IACS, worse than 89% of precious metal grades
  • Poor heat conductor — 38 W/m·K (22 BTU/hr·ft·°F), worse than 87% of precious metal grades
  • Limited formability — 65/100, worse than 86% of precious metal grades

Pt950 Stress Relieved properties

Typical room-temperature values for Pt950 Stress Relieved; 20 are specific to this condition. Other listed values are Pt950 reference data and may not represent this condition. Bars are the position among precious metal grades.

Physical3

Pt950 Stress Relieved has a density of 20.1 g/cm³ (0.726 lb/in³), heavier than 94% of precious metal grades. It melts at 1,755°C (3,191 °F).

Density20.1 g/cm³0.73 lb/in³
Melting Point (Solidus)1,755°C3,191 °F
Liquidus Temperature1,780°C3,236 °F

Mechanical11

Pt950 Stress Relieved has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 400 MPa (58 ksi) — stronger than 81% of precious metal grades. Elongation at break is 20% and the elastic modulus is 172 GPa (24.9 Msi).

Elastic (Young's) Modulus172 GPa24.9 Msi
Shear Modulus62 GPa9 Msi
Bulk Modulus235 GPa34.1 Msi
Poisson's Ratio0.39
Tensile Strength (Ultimate)400 MPa58 ksi
Yield Strength (0.2% offset)250 MPa36.3 ksi
Elongation at Break20%
Shear Strength270 MPa39.2 ksi
Fatigue Strength (Endurance Limit)190 MPa27.6 ksi
Hardness, Brinell142 HB
Hardness, Vickers150 HV

Thermal6

Pt950 Stress Relieved is rated for continuous service to 600°C (1,112 °F). It conducts heat at 38 W/m·K (22 BTU/hr·ft·°F), worse than 87% of precious metal grades. Thermal expansion is 9 µm/m·K (5 µin/in·°F).

Thermal Conductivity38 W/m·K22 BTU/hr·ft·°F
Specific Heat Capacity133 J/kg·K0.03 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)9 µm/m·K5 µin/in·°F
Latent Heat of Fusion110 J/g47.3 BTU/lb
Max Service Temperature (continuous)600°C1,112 °F
Min Service Temperature-250°C-418 °F

Electrical3

Pt950 Stress Relieved conducts electricity at 7 % IACS, worse than 89% of precious metal grades.

Electrical Conductivity7 % IACS
Electrical Resistivity2.46×10⁻⁷ Ω·m9.69 µΩ·in
Magnetic Responsenon-magnetic

Chemical & Environmental3

Corrosion resistance is excellent (100/100), better than 98% of precious metal grades.

Galvanic Potential (seawater, vs SCE)0.3 V
Corrosion ResistanceExcellent100/100
Chemical Resistance Summary—

Sustainability4

Producing a kilogram of Pt950 Stress Relieved takes about 250,000 MJ of energy and emits 16,000 kg of CO₂ — more than 95% of precious metal grades. Typical recycled content is 35%.

Embodied Energy (primary production)250,000 MJ/kg1.07×10⁸ BTU/lb
Embodied Carbon (primary production)16,000 kg CO₂/kg
Embodied Water200,000 L/kg23,965 gal/lb
Typical Recycled Content35%

Manufacturability8

Pt950 Stress Relieved's machinability is fair (35/100, worse than 73% of precious metal grades); weldability very good (80/100); formability good (65/100).

MachinabilityFair35/100
Machinability Rating (AISI 1212 = 100 %)30%
WeldabilityVery good80/100
Formability (cold)Good65/100
CastabilityVery good70/100
Brazeability / SolderabilityExcellent85/100
PolishabilityExcellent95/100
Anodizing Response—

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with Pt950 Stress Relieved

Is Pt950 easy to machine?

Highly prone to sticking and built-up edge: use sharp positive-rake carbide or diamond tools at high speed and low feed with generous lubrication. Recover all chips and grinding dust for refining.

Can Pt950 be welded?

Laser spot welding, pulsed TIG and oxy-hydrogen torch welding all perform well and can be run autogenously without flux. Avoid Pb, Bi, S and Si contamination and contact with silicon-bearing refractories, which cause high-temperature embrittlement.

Can Pt950 be formed, bent or molded?

Cold formability in the annealed temper is excellent, above 90 % deformation, with interstage anneals at 900–1000 °C. Casting requires vacuum or centrifugal equipment, zirconia or yttria shells and a pouring temperature of about 1850–1900 °C.

What surface finishes work on Pt950?

Takes a mirror polish directly and needs no plating; sandblasting, brushing and laser engraving are all practical. Use dust extraction during polishing to recover precious metal fines.

Pt950 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.

ElementSpec limit (wt %)Nominal
RuPt950Ru: most common wrought/cast jewellery variant0 – 55
IrPt950Ir (Pt-Ir 950): best ductility; wire, electrodes, medical0 – 5—
CoPt950Co: best casting flow, high as-cast hardness, weakly magnetic0 – 5—
CuPt950Cu: lower cost, medium hardness, common in EU/Asia jewellery0 – 5—
PdPt950Pd: soft, easily worked; used for prongs and solder joints0 – 5—
WPt950W: high-hardness wrought variant0 – 5—
other (total)Fe, Si, Pb, Bi limited; Pb/Bi cause high-temp embrittlement0 – 0.15—
PtPt950 / 950 hallmark requires at least 95.0 wt% platinum≥ 95 (balance)—

Pt950 Stress Relieved — frequently asked

What is Pt950 Stress Relieved used for?

Pt950 Stress Relieved is typically used for bridal jewelry and wedding bands, watch cases and bezels, laboratory crucibles and dishes, electrodes, thermocouple sheaths and medical implant components. In short: premium platinum jewelry alloy.

What is the yield strength of Pt950 Stress Relieved?

Pt950 Stress Relieved has a typical yield strength of 250 MPa (36.3 ksi) and a tensile strength of 400 MPa (58 ksi) — stronger than 81% of precious metal grades. Strength varies by condition: see the 4 listed tempers.

Is Pt950 Stress Relieved easy to machine?

Not especially — machinability is rated fair (35/100, worse than 73% of precious metal grades). Highly prone to sticking and built-up edge: use sharp positive-rake carbide or diamond tools at high speed and low feed with generous lubrication. Recover all chips and grinding dust for refining.

Can Pt950 Stress Relieved be welded?

Yes — weldability is rated very good (80/100). Laser spot welding, pulsed TIG and oxy-hydrogen torch welding all perform well and can be run autogenously without flux. Avoid Pb, Bi, S and Si contamination and contact with silicon-bearing refractories, which cause high-temperature embrittlement.

What surface finishes work on Pt950 Stress Relieved?

Takes a mirror polish directly and needs no plating; sandblasting, brushing and laser engraving are all practical. Use dust extraction during polishing to recover precious metal fines.

Can Pt950 Stress Relieved be formed, bent or molded?

Cold formability in the annealed temper is excellent, above 90 % deformation, with interstage anneals at 900–1000 °C. Casting requires vacuum or centrifugal equipment, zirconia or yttria shells and a pouring temperature of about 1850–1900 °C.

What is the maximum service temperature of Pt950 Stress Relieved?

Pt950 Stress Relieved 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.

Sources

  1. ASM Handbook Vol.2: Properties and Selection — Nonferrous Alloys (Precious Metals) — ASM International (1990)
  2. ASM Handbook Vol.13B: Corrosion — Materials (Platinum Group Metals) — ASM International (2005)
  3. Platinum jewellery alloy data (Pt950Ru / Pt950Ir / Pt950Co) — Johnson Matthey / PGM refiners (2021)
  4. ASTM B684 / B561 — Platinum and platinum alloy products — ASTM (2019)
  5. Precious metal LCA / embodied energy datasets — Granta / ecoinvent (2022)

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.