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Nickel Alloy Alloy 59 vs Alloy 686

Nickel Alloy · grade comparison

Nickel Alloy Alloy 59 and Alloy 686 are both nickel alloy grades. Alloy 686 is the stronger of the two: yield strength 380 MPa (55.1 ksi) against 360 MPa (52.2 ksi) for Alloy 59, about 6% more. Alloy 686 is the more ductile: elongation 60% versus 50% for Alloy 59, and Alloy 59 is harder (200 HB vs 190 HB). Alloy 59 conducts heat better (10.4 W/m·K vs 9.1 W/m·K).

Alloy 686Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

Alloy 59 vs Alloy 686: properties

Alloy 59Alloy 686

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
208 GPa30.2 Msi

Shear Modulus

80 GPa11.6 Msi
79 GPa11.5 Msi

Bulk Modulus

184 GPa26.7 Msi
182 GPa26.4 Msi

Tensile Strength (Ultimate)

740 MPa107 ksi
760 MPa110 ksi

Yield Strength (0.2% offset)

360 MPa52.2 ksi
380 MPa55.1 ksi

Elongation at Break

50%
60%

Compressive Strength

360 MPa52.2 ksi
390 MPa56.6 ksi

Shear Strength

450 MPa65.3 ksi
480 MPa69.6 ksi

Charpy V-Notch Impact (RT)

200 J148 ft·lbf
250 J184 ft·lbf

Hardness, Brinell

200 HB
190 HB

Hardness, Rockwell B

92 HRB
88 HRB

Hardness, Vickers

210 HV
200 HV

Same in both: Poisson's Ratio 0.31 · Reduction in Area 65% · Fatigue Strength (Endurance Limit) 300 MPa43.5 ksi

Physical

Density and transition temperatures.

Density

8.6 g/cm³0.31 lb/in³
8.73 g/cm³0.32 lb/in³

Melting Point (Solidus)

1,310°C2,390 °F
1,338°C2,440 °F

Liquidus Temperature

1,360°C2,480 °F
1,380°C2,516 °F

Thermal

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

Thermal Conductivity

10.4 W/m·K6 BTU/hr·ft·°F
9.1 W/m·K5.3 BTU/hr·ft·°F

Specific Heat Capacity

420 J/kg·K0.1 BTU/lb·°F
390 J/kg·K0.09 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

12.4 µm/m·K6.9 µin/in·°F
12.2 µm/m·K6.8 µin/in·°F

Same in both: Latent Heat of Fusion 290 J/g125 BTU/lb · Max Service Temperature (continuous) 1,000°C1,832 °F · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

1.3 % IACS
1.4 % IACS

Electrical Resistivity

1.29×10⁻⁶ Ω·m50.8 µΩ·in
1.24×10⁻⁶ Ω·m48.8 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.08 V
-0.12 V

Corrosion Resistance

93 / 100
95 / 100

Manufacturability

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

Weldability

88 / 100
80 / 100

Formability (cold)

75 / 100
70 / 100

Brazeability / Solderability

60 / 100
55 / 100

Polishability

80 / 100
75 / 100

Castability

—
25 / 100

Same in both: Machinability 18 / 100 · Machinability Rating (AISI 1212 = 100 %) 12%

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

180 MJ/kg77,386 BTU/lb
150 MJ/kg64,488 BTU/lb

Embodied Carbon (primary production)

14 kg CO₂/kg
12.5 kg CO₂/kg

Embodied Water

250 L/kg30 gal/lb
320 L/kg38.3 gal/lb

Typical Recycled Content

40%
35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

86 kN·m/kg
87 kN·m/kg

Specific Stiffness (E / density)

24.4 MN·m/kg
23.8 MN·m/kg

Modulus of Resilience

309 kJ/m³
347 kJ/m³

Thermal Diffusivity

2.9 mm²/s
2.7 mm²/s

Same in both: Thermal Shock Resistance Index 3

Strength versus weight

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

2005001,0006.577.588.59Density (g/cm³)Yield strength (MPa) — log scaleAlloy 59Alloy 686

Manufacturing and finishing

CapabilityAlloy 59Alloy 686
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Both take the same 3 finishes: Gold Plating, Plasma Spray, Silver Plating.

Alloy 59 vs Alloy 686 — frequently asked

Is Alloy 686 stronger than Alloy 59?

Yes. Alloy 686 has a typical yield strength of 380 MPa (55.1 ksi) against 360 MPa (52.2 ksi) for Alloy 59 — about 6% more. Tensile strength is 760 MPa (110 ksi) vs 740 MPa (107 ksi).

Which is cheaper, Alloy 59 or Alloy 686?

Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which welds better, Alloy 59 or Alloy 686?

Alloy 59. Its weldability rates excellent (88/100) against very good (80/100) for Alloy 686.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Alloy 59 and Alloy 686 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.