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Precious Metal AuNi5 vs Silver 999

Precious Metal · grade comparison

Precious Metal AuNi5 and Silver 999 are both precious metal grades. AuNi5 is the stronger of the two: yield strength 610 MPa (88.5 ksi) against 55 MPa (7.98 ksi) for Silver 999, about 11 times as much; tensile strength follows at 700 MPa (102 ksi) vs 140 MPa (20.3 ksi). In exchange, Silver 999 is the more ductile: elongation 48% versus 3% for AuNi5, and AuNi5 is harder (200 HV vs 27 HV). Silver 999 is lighter (10.49 g/cm³ vs 18.3 g/cm³ for AuNi5) and AuNi5 is stiffer (105 GPa vs 76 GPa). On the shop floor, AuNi5 sits in a lower cost tier (high, $$$$) than Silver 999 (specialty, $$$$$).

AuNi5Choose it when strength drives the design, or when cost is the deciding factor.

Silver 999Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.

AuNi5 vs Silver 999: properties

AuNi5Silver 999

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

105 GPa15.2 Msi
76 GPa11 Msi

Shear Modulus

38 GPa5.5 Msi
29.5 GPa4.3 Msi

Bulk Modulus

175 GPa25.4 Msi
100 GPa14.5 Msi

Poisson's Ratio

0.39
0.37

Tensile Strength (Ultimate)

700 MPa102 ksi
140 MPa20.3 ksi

Yield Strength (0.2% offset)

610 MPa88.5 ksi
55 MPa8 ksi

Elongation at Break

3%
48%

Shear Strength

420 MPa60.9 ksi
95 MPa13.8 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
60 MPa8.7 ksi

Hardness, Vickers

200 HV
27 HV

Reduction in Area

—
85%

Hardness, Brinell

—
25 HB

Physical

Density and transition temperatures.

Density

18.3 g/cm³0.66 lb/in³
10.49 g/cm³0.38 lb/in³

Melting Point (Solidus)

990°C1,814 °F
962°C1,763 °F

Liquidus Temperature

1,020°C1,868 °F
962°C1,763 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

60 W/m·K34.7 BTU/hr·ft·°F
429 W/m·K248 BTU/hr·ft·°F

Specific Heat Capacity

140 J/kg·K0.03 BTU/lb·°F
235 J/kg·K0.06 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

14.3 µm/m·K7.9 µin/in·°F
19.6 µm/m·K10.9 µin/in·°F

Latent Heat of Fusion

68 J/g29.2 BTU/lb
105 J/g45.1 BTU/lb

Max Service Temperature (continuous)

200°C392 °F
250°C482 °F

Same in both: Min Service Temperature -200°C-328 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

13 % IACS
106 % IACS

Electrical Resistivity

1.3×10⁻⁷ Ω·m5.12 µΩ·in
1.59×10⁻⁸ Ω·m0.626 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

0.22 V
-0.11 V

Corrosion Resistance

94 / 100
80 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability Rating (AISI 1212 = 100 %)

30%
55%

Formability (cold)

30 / 100
98 / 100

Castability

70 / 100
85 / 100

Brazeability / Solderability

85 / 100
96 / 100

Polishability

92 / 100
98 / 100

Same in both: Machinability 40 / 100 · Weldability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

185,000 MJ/kg7.95×10⁷ BTU/lb
1,550 MJ/kg666,381 BTU/lb

Embodied Carbon (primary production)

15,000 kg CO₂/kg
96 kg CO₂/kg

Embodied Water

250,000 L/kg29,957 gal/lb
250 L/kg30 gal/lb

Typical Recycled Content

40%
30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

38 kN·m/kg
13 kN·m/kg

Specific Stiffness (E / density)

5.7 MN·m/kg
7.2 MN·m/kg

Modulus of Resilience

1,772 kJ/m³
20 kJ/m³

Thermal Diffusivity

23.4 mm²/s
174 mm²/s

Thermal Shock Resistance Index

28
40

Strength versus weight

Yield strength against density for every precious metal grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

50100200500101520Density (g/cm³)Yield strength (MPa) — log scaleSilver 999AuNi5

Manufacturing and finishing

CapabilityAuNi5Silver 999
Default condition—O
Relative cost$$$$ High$$$$$ Specialty
Min. machined wall——
Best machined surface——

AuNi5 vs Silver 999 — frequently asked

Is AuNi5 stronger than Silver 999?

Yes. AuNi5 has a typical yield strength of 610 MPa (88.5 ksi) against 55 MPa (7.98 ksi) for Silver 999 — about 11 times as much. Tensile strength is 700 MPa (102 ksi) vs 140 MPa (20.3 ksi).

Which is cheaper, AuNi5 or Silver 999?

AuNi5 is the lower-cost material: it sits in the high tier ($$$$) while Silver 999 is specialty ($$$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

When should I choose AuNi5 over Silver 999?

Pick AuNi5 when strength drives the design, or when cost is the deciding factor. Pick Silver 999 when the part is bent, formed or impact-loaded, or when weight is the constraint.

Ready to make it?

Upload a CAD file and FabDigit prices the part in AuNi5 and Silver 999 side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.