Precious Metal Pt95Co5-H01
Supply condition
H01 = quarter hard
Use lightly cold-worked (about 15%) sheet or wire for ring shanks and light structural parts that must balance formability against resistance to deformation.
Values for the H01 condition
Other Pt95Co5 tempers and conditions
Pt95Co5 is listed in 5 conditions; see the grade overview at Pt95Co5.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Choose the annealed soft state before or after cold working sheet, wire and tube; 32% elongation suits hand forging, drawing and bezel setting, at only 190 MPa yield. | 190 | 430 | 32 | 124 HB | 7 % IACS |
ACDefault Spheroidize annealed | Pick the normal as-investment-cast delivery state for lost-wax jewellery blanks: fine grain and good density allow direct filing and polishing, with 20% elongation. | 250 | 480 | 20 | 128 HB | 7 % IACS |
H01This page Quarter hard | Use lightly cold-worked (about 15%) sheet or wire for ring shanks and light structural parts that must balance formability against resistance to deformation. | 400 | 550 | 15 | 152 HB | 6.8 % IACS |
Half hard | Pick half-hard stock cold worked about 30–35% for prongs, clasps and chain parts needing rigidity; 520 MPa yield comes with elongation reduced to 8%. | 520 | 640 | 8 | 10 HRC | 6.8 % IACS |
Full hard | Choose heavily cold-worked wire or strip (50%+ reduction) for spring clasps and earring posts where hardness and springiness are highest; elongation drops to 3%. | 620 | 720 | 3 | 18 HRC | 6.7 % IACS |
What is Pt95Co5-H01?
Pt95Co5-H01 is Pt95Co5 supplied in the H01 condition — use lightly cold-worked (about 15%) sheet or wire for ring shanks and light structural parts that must balance formability against resistance to deformation. Pt95Co5-H01 has a yield strength of 400 MPa (58 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 96% of precious metal grades. Elongation at break is 15% and the elastic modulus is 172 GPa (24.9 Msi). Pt95Co5-H01 has a density of 20 g/cm³ (0.723 lb/in³), heavier than 93% of precious metal grades. It melts at 1,745°C (3,173 °F). AC is the default condition FabDigit quotes; H01 is available on request or by drawing note.
Advantages
- High strength — 400 MPa (58 ksi), better than 96% 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
- Good corrosion resistance — 96/100, better than 85% of precious metal grades
Limitations
- Heavy — 20 g/cm³ (0.723 lb/in³), worse than 93% of precious metal grades
- Poor heat conductor — 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 90% of precious metal grades
- Low electrical conductivity — 6.8 % IACS, worse than 90% of precious metal grades
- Limited ductility — 15%, worse than 86% of precious metal grades
- Limited formability — 65/100, worse than 86% of precious metal grades
Pt95Co5-H01 properties
Typical room-temperature values for Pt95Co5-H01; 20 are specific to this condition. Other listed values are Pt95Co5 reference data and may not represent this condition. Bars are the position among precious metal grades.
Physical3
Pt95Co5-H01 has a density of 20 g/cm³ (0.723 lb/in³), heavier than 93% of precious metal grades. It melts at 1,745°C (3,173 °F).
Mechanical14
Pt95Co5-H01 has a yield strength of 400 MPa (58 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 96% of precious metal grades. Elongation at break is 15% and the elastic modulus is 172 GPa (24.9 Msi).
Thermal6
Pt95Co5-H01 is rated for continuous service to 400°C (752 °F). It conducts heat at 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 90% of precious metal grades. Thermal expansion is 9.2 µm/m·K (5.11 µin/in·°F).
Electrical3
Pt95Co5-H01 conducts electricity at 6.8 % IACS, worse than 90% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (96/100), better than 85% of precious metal grades.
Sustainability4
Producing a kilogram of Pt95Co5-H01 takes about 250,000 MJ of energy and emits 13,000 kg of CO₂ — more than 95% of precious metal grades. Typical recycled content is 35%.
Manufacturability8
Pt95Co5-H01's machinability is fair (40/100, worse than 60% of precious metal grades); weldability very good (80/100); formability good (65/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Pt95Co5-H01
Is Pt95Co5 easy to machine?
Tough and gummy with a tendency to build-up edge — use sharp, high positive-rake carbide or diamond tooling at low speed with light feeds and ample lubricant. Single-point diamond turning gives a mirror surface on jewelry parts.
Can Pt95Co5 be welded?
Laser and PUK pulse-arc welding work well with matching Pt950Co filler wire. With oxy-acetylene, keep the flame slightly reducing to limit cobalt oxidation and avoid overheating, which coarsens the grain.
Can Pt95Co5 be formed, bent or molded?
Investment casting is the primary route: mould temperature 850–1000 °C, pour at 1800–1850 °C, induction vacuum or centrifugal. Castings can be annealed and cold formed; interanneal once cold work exceeds about 40 %.
What surface finishes work on Pt95Co5?
Polishes more quickly than Pt950Ru; step through silicon carbide, then alumina, then chromium oxide for a mirror finish. Rhodium plating is not required, though a thin rhodium flash can be applied for an extra-white tone; blasted and brushed textures remain stable and do not tarnish.
Pt95Co5 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 |
|---|---|---|
| Cosolid-solution strengthener; casting flow, fine grain, weak magnetism | 4.5 – 5.5 | 5 |
| Other (Ir, Ru, Cu, Fe )total impurities, normally well below 0.1% | ≤ 0.5 | — |
| Pt950 hallmark requires ≥95.0% Pt (GB 11887 / ISO 9202) | ≥ 95 (balance) | — |
Pt95Co5-H01 — frequently asked
What is Pt95Co5-H01 used for?
Pt95Co5-H01 is typically used for cast platinum jewelry, ring settings and watch cases. In short: standard platinum casting alloy; fast-polishing Pt950 grade; bright white at 950 fineness.
What is the yield strength of Pt95Co5-H01?
Pt95Co5-H01 has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 96% of precious metal grades. Strength varies by condition: see the 5 listed tempers.
Is Pt95Co5-H01 easy to machine?
Not especially — machinability is rated fair (40/100, worse than 60% of precious metal grades). Tough and gummy with a tendency to build-up edge — use sharp, high positive-rake carbide or diamond tooling at low speed with light feeds and ample lubricant. Single-point diamond turning gives a mirror surface on jewelry parts.
Can Pt95Co5-H01 be welded?
Yes — weldability is rated very good (80/100). Laser and PUK pulse-arc welding work well with matching Pt950Co filler wire. With oxy-acetylene, keep the flame slightly reducing to limit cobalt oxidation and avoid overheating, which coarsens the grain.
What surface finishes work on Pt95Co5-H01?
Polishes more quickly than Pt950Ru; step through silicon carbide, then alumina, then chromium oxide for a mirror finish. Rhodium plating is not required, though a thin rhodium flash can be applied for an extra-white tone; blasted and brushed textures remain stable and do not tarnish.
Can Pt95Co5-H01 be formed, bent or molded?
Investment casting is the primary route: mould temperature 850–1000 °C, pour at 1800–1850 °C, induction vacuum or centrifugal. Castings can be annealed and cold formed; interanneal once cold work exceeds about 40 %.
What is the maximum service temperature of Pt95Co5-H01?
Pt95Co5-H01 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Pt95Co5-AC and Pt95Co5-H04?
AC is the default condition — pick the normal as-investment-cast delivery state for lost-wax jewellery blanks: fine grain and good density allow direct filing and polishing, with 20% elongation. H04: choose heavily cold-worked wire or strip (50%+ reduction) for spring clasps and earring posts where hardness and springiness are highest; elongation drops to 3%. Yield strength is 250 MPa in AC versus 620 MPa in H04.
Sources
- ISO 9202 Jewellery — Fineness of precious metal alloys — ISO (2019)
- Platinum Metals Review — platinum jewellery alloys (properties of Pt-Co, Pt-Ru, Pt-Ir) — Johnson Matthey (2005)
- ASM Handbook Vol. 2 — Properties of Precious Metals and Alloys — ASM International (1990)
- Platinum casting alloy technical data (Pt950/Co) — Hoover & Strong / Stuller (2023)
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.