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Precious Metal AuCo5-H02

Supply condition

H02 = half hard

Compromise temper for formed contact clips that still need moderate bend forming after rolling or drawing.

High cost $$$$

Values for the H02 condition

Other AuCo5 tempers and conditions

AuCo5 is listed in 4 conditions; see the grade overview at AuCo5.

Compare all 4 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
Annealed
Pick for deep forming, riveting, cladding/bonding of contact buttons and for wire that must be bent tightly before hardening.1303303095 HV13 % IACS
H02This page
Half hard
Compromise temper for formed contact clips that still need moderate bend forming after rolling or drawing.4505508160 HV13.5 % IACS
H04Default
Full hard
Standard stock condition for contact springs, probe and connector wire needing high contact force retention and wear resistance.6507503200 HV14 % IACS
Cold worked + age hardened
Highest hardness and wear life for sliding/rotating contacts and slip rings; ageing precipitates Co and also lowers resistivity slightly.8009002255 HV20 % IACS

What is AuCo5-H02?

AuCo5-H02 is AuCo5 supplied in the H02 condition — compromise temper for formed contact clips that still need moderate bend forming after rolling or drawing. AuCo5-H02 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 97% of precious metal grades. Elongation at break is 8% and the elastic modulus is 95 GPa (13.8 Msi). AuCo5-H02 has a density of 18.2 g/cm³ (0.658 lb/in³), heavier than 88% of precious metal grades. It melts at 996°C (1,825 °F). H04 is the default condition FabDigit quotes; H02 is available on request or by drawing note.

Advantages

  • High strength — 450 MPa (65.3 ksi), better than 97% of precious metal grades
  • Polishes to a fine finish — 95/100, better than 86% of precious metal grades

Limitations

  • Limited ductility — 8%, worse than 92% of precious metal grades
  • Limited formability — 50/100, worse than 90% of precious metal grades
  • Heavy — 18.2 g/cm³ (0.658 lb/in³), worse than 88% of precious metal grades
  • High embodied carbon — 12,000 kg CO₂/kg, worse than 76% of precious metal grades

AuCo5-H02 properties

Typical room-temperature values for AuCo5-H02; 11 are specific to this condition. Other listed values are AuCo5 reference data and may not represent this condition. Bars are the position among precious metal grades.

Physical3

AuCo5-H02 has a density of 18.2 g/cm³ (0.658 lb/in³), heavier than 88% of precious metal grades. It melts at 996°C (1,825 °F).

Density18.2 g/cm³0.66 lb/in³
Melting Point (Solidus)996°C1,825 °F
Liquidus Temperature1,025°C1,877 °F

Mechanical10

AuCo5-H02 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 97% of precious metal grades. Elongation at break is 8% and the elastic modulus is 95 GPa (13.8 Msi).

Elastic (Young's) Modulus95 GPa13.8 Msi
Shear Modulus35 GPa5.1 Msi
Bulk Modulus165 GPa23.9 Msi
Poisson's Ratio0.41
Tensile Strength (Ultimate)550 MPa79.8 ksi
Yield Strength (0.2% offset)450 MPa65.3 ksi
Elongation at Break8%
Shear Strength330 MPa47.9 ksi
Fatigue Strength (Endurance Limit)230 MPa33.4 ksi
Hardness, Vickers160 HV

Thermal6

AuCo5-H02 is rated for continuous service to 250°C (482 °F). It conducts heat at 65 W/m·K (37.6 BTU/hr·ft·°F), worse than 67% of precious metal grades. Thermal expansion is 14.3 µm/m·K (7.94 µin/in·°F).

Thermal Conductivity65 W/m·K37.6 BTU/hr·ft·°F
Specific Heat Capacity140 J/kg·K0.03 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)14.3 µm/m·K7.9 µin/in·°F
Latent Heat of Fusion70 J/g30.1 BTU/lb
Max Service Temperature (continuous)250°C482 °F
Min Service Temperature-269°C-452 °F

Electrical3

AuCo5-H02 conducts electricity at 13.5 % IACS, worse than 71% of precious metal grades.

Electrical Conductivity13.5 % IACS
Electrical Resistivity1.25×10⁻⁷ Ω·m4.92 µΩ·in
Magnetic Responseweakly magnetic

Chemical & Environmental3

Corrosion resistance is excellent (92/100), better than 73% of precious metal grades.

Galvanic Potential (seawater, vs SCE)0.25 V
Corrosion ResistanceExcellent92/100
Chemical Resistance SummaryImmune to atmospheric oxidation, sulfidation and most acids/alkalis; the cobalt phase can be leached by hot mineral acids, and the alloy dissolves in aqua regia, free chlorine/bromine and cyanide solutions.

Sustainability4

Producing a kilogram of AuCo5-H02 takes about 180,000 MJ of energy and emits 12,000 kg of CO₂ — more than 77% of precious metal grades. Typical recycled content is 35%.

Embodied Energy (primary production)180,000 MJ/kg7.74×10⁷ BTU/lb
Embodied Carbon (primary production)12,000 kg CO₂/kg
Embodied Water150,000 L/kg17,974 gal/lb
Typical Recycled Content35%

Manufacturability8

AuCo5-H02's machinability is fair (42/100, worse than 53% of precious metal grades); weldability very good (70/100); formability fair (50/100).

MachinabilityFair42/100
Machinability Rating (AISI 1212 = 100 %)30%
WeldabilityVery good70/100
Formability (cold)Fair50/100
CastabilityGood60/100
Brazeability / SolderabilityExcellent90/100
PolishabilityExcellent95/100
Anodizing Responsen/a — noble metal, does not anodize; supplied as bare or as clad/plated contact layer

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

Working with AuCo5-H02

Is AuCo5 easy to machine?

Turns and slits like soft gold — gummy and prone to smearing; use polished carbide/diamond tools, high speed, light feeds, and capture all chips for refining.

Can AuCo5 be welded?

Resistance, percussion and laser welding of contact tips/rivets to Cu, CuBe or Ni substrates is standard; avoid fusion welding large sections to prevent Co-rich segregation.

Can AuCo5 be formed, bent or molded?

Excellent cold formability when annealed (rolling, drawing, stamping, cladding onto Cu alloy strip); intermediate anneals near 600–700 °C in inert/reducing atmosphere, then final cold work or age hardening.

What surface finishes work on AuCo5?

Cannot be anodized; barrel- or wheel-polishes to a mirror finish, is often used as an inlay/clad layer, and needs no protective coating since the surface stays oxide- and sulfide-free.

AuCo5 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
Cohardening addition; partly in solid solution, partly as fine precipitate4.5 – 5.55
Nioptional grain refiner / incidental0 – 0.2—
other, eachFe, Cu, Ag impurities0 – 0.05—
Au≈95 wt % (about 2280 fine equivalent)balance—

AuCo5-H02 — frequently asked

What is AuCo5-H02 used for?

AuCo5-H02 is typically used for telecom relay contacts, connector plating substitutes, low-current signal switches and precision instrument contacts. In short: hard gold contact alloy; stable low contact resistance; wear-resistant versus pure gold.

What is the yield strength of AuCo5-H02?

AuCo5-H02 has a typical yield strength of 450 MPa (65.3 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 97% of precious metal grades. Strength varies by condition: see the 4 listed tempers.

Is AuCo5-H02 easy to machine?

Not especially — machinability is rated fair (42/100, worse than 53% of precious metal grades). Turns and slits like soft gold — gummy and prone to smearing; use polished carbide/diamond tools, high speed, light feeds, and capture all chips for refining.

Can AuCo5-H02 be welded?

Yes — weldability is rated very good (70/100). Resistance, percussion and laser welding of contact tips/rivets to Cu, CuBe or Ni substrates is standard; avoid fusion welding large sections to prevent Co-rich segregation.

What surface finishes work on AuCo5-H02?

Cannot be anodized; barrel- or wheel-polishes to a mirror finish, is often used as an inlay/clad layer, and needs no protective coating since the surface stays oxide- and sulfide-free.

Can AuCo5-H02 be formed, bent or molded?

Excellent cold formability when annealed (rolling, drawing, stamping, cladding onto Cu alloy strip); intermediate anneals near 600–700 °C in inert/reducing atmosphere, then final cold work or age hardening.

What is the maximum service temperature of AuCo5-H02?

AuCo5-H02 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between AuCo5-H04 and AuCo5-O?

H04 is the default condition — standard stock condition for contact springs, probe and connector wire needing high contact force retention and wear resistance. O: pick for deep forming, riveting, cladding/bonding of contact buttons and for wire that must be bent tightly before hardening. Yield strength is 650 MPa in H04 versus 130 MPa in O.

Sources

  1. ASM Handbook, Vol. 2: Properties and Selection — Nonferrous Alloys and Special-Purpose Materials (precious metals and electrical contact materials) — ASM International (1990)
  2. ASM Alloy Phase Diagrams Database — Au-Co system — ASM International (2016)
  3. Electrical Contacts: Principles and Applications (contact materials for low-level signal contacts) — CRC Press (2013)
  4. Precious-metal contact wire, strip and clad material data (Deringer-Ney / Materion class products) — producer datasheets (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.