FabDigitFabDigit

Precious Metal AuNi vs Silver 999

Precious Metal · grade comparison

Precious Metal AuNi and Silver 999 are both precious metal grades. AuNi is the stronger of the two: yield strength 620 MPa (89.9 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 AuNi, and AuNi is harder (215 HV vs 27 HV). Silver 999 is lighter (10.49 g/cm³ vs 18.3 g/cm³ for AuNi) and AuNi is stiffer (95 GPa vs 76 GPa). On the shop floor, AuNi welds better (very good vs good) and AuNi sits in a lower cost tier (high, $$$$) than Silver 999 (specialty, $$$$$).

AuNiChoose it when strength drives the design, or when the part sees heat.

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

AuNi vs Silver 999: properties

AuNiSilver 999

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

95 GPa13.8 Msi
76 GPa11 Msi

Shear Modulus

35 GPa5.1 Msi
29.5 GPa4.3 Msi

Bulk Modulus

175 GPa25.4 Msi
100 GPa14.5 Msi

Poisson's Ratio

0.41
0.37

Tensile Strength (Ultimate)

700 MPa102 ksi
140 MPa20.3 ksi

Yield Strength (0.2% offset)

620 MPa89.9 ksi
55 MPa8 ksi

Elongation at Break

3%
48%

Shear Strength

440 MPa63.8 ksi
95 MPa13.8 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
60 MPa8.7 ksi

Hardness, Vickers

215 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)

955°C1,751 °F
962°C1,763 °F

Liquidus Temperature

975°C1,787 °F
962°C1,763 °F

Thermal

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

Thermal Conductivity

58 W/m·K33.5 BTU/hr·ft·°F
429 W/m·K248 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

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

Latent Heat of Fusion

75 J/g32.2 BTU/lb
105 J/g45.1 BTU/lb

Max Service Temperature (continuous)

400°C752 °F
250°C482 °F

Min Service Temperature

-250°C-418 °F
-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)

0.25 V
-0.11 V

Corrosion Resistance

96 / 100
80 / 100

Manufacturability

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

Machinability

45 / 100
40 / 100

Machinability Rating (AISI 1212 = 100 %)

40%
55%

Weldability

75 / 100
60 / 100

Formability (cold)

55 / 100
98 / 100

Castability

70 / 100
85 / 100

Brazeability / Solderability

90 / 100
96 / 100

Polishability

95 / 100
98 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

240,000 MJ/kg1.03×10⁸ BTU/lb
1,550 MJ/kg666,381 BTU/lb

Embodied Carbon (primary production)

24,000 kg CO₂/kg
96 kg CO₂/kg

Embodied Water

200,000 L/kg23,965 gal/lb
250 L/kg30 gal/lb

Same in both: Typical Recycled Content 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)

5.2 MN·m/kg
7.2 MN·m/kg

Modulus of Resilience

2,023 kJ/m³
20 kJ/m³

Thermal Diffusivity

21.9 mm²/s
174 mm²/s

Thermal Shock Resistance Index

30
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 999AuNi

Manufacturing and finishing

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

AuNi vs Silver 999 — frequently asked

Is AuNi stronger than Silver 999?

Yes. AuNi has a typical yield strength of 620 MPa (89.9 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, AuNi or Silver 999?

AuNi 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.

Which is easier to machine, AuNi or Silver 999?

AuNi, by a small margin. Both rate fair for machinability — 45/100 against 40/100 for Silver 999; for welding the order is AuNi first (very good, 75/100) then Silver 999 (good, 60/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in AuNi 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.