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Nickel Alloy CW-12MW vs IN-939

Nickel Alloy · grade comparison

Nickel Alloy CW-12MW and IN-939 are both nickel alloy grades. IN-939 is the stronger of the two: yield strength 780 MPa (113 ksi) against 350 MPa (50.8 ksi) for CW-12MW, about 123% more; tensile strength follows at 1,100 MPa (160 ksi) vs 550 MPa (79.8 ksi). In exchange, CW-12MW is the more ductile: elongation 10% versus 5.5% for IN-939, and IN-939 is harder (37 HRC vs 15 HRC). IN-939 is lighter (8.16 g/cm³ vs 8.94 g/cm³ for CW-12MW) and IN-939 runs hotter in service (850°C vs 650°C continuous). On the shop floor, CW-12MW machines more easily (poor vs not recommended) and CW-12MW welds better (good vs poor).

CW-12MWChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

IN-939Choose it when strength drives the design, or when weight is the constraint.

CW-12MW vs IN-939: properties

CW-12MWIN-939

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

78 GPa11.3 Msi
79 GPa11.5 Msi

Bulk Modulus

180 GPa26.1 Msi
175 GPa25.4 Msi

Tensile Strength (Ultimate)

550 MPa79.8 ksi
1,100 MPa160 ksi

Yield Strength (0.2% offset)

350 MPa50.8 ksi
780 MPa113 ksi

Elongation at Break

10%
5.5%

Reduction in Area

12%
7%

Shear Strength

385 MPa55.8 ksi
680 MPa98.6 ksi

Fatigue Strength (Endurance Limit)

220 MPa31.9 ksi
400 MPa58 ksi

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
—

Hardness, Brinell

200 HB
—

Hardness, Rockwell B

94 HRB
—

Hardness, Rockwell C

15 HRC
37 HRC

Fracture Toughness (K_IC)

—
75 MPa·√m68.3 ksi·√in

Hardness, Vickers

—
360 HV

Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Poisson's Ratio 0.31

Physical

Density and transition temperatures.

Density

8.94 g/cm³0.32 lb/in³
8.16 g/cm³0.29 lb/in³

Melting Point (Solidus)

1,275°C2,327 °F
1,290°C2,354 °F

Liquidus Temperature

1,355°C2,471 °F
1,350°C2,462 °F

Thermal

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

Thermal Conductivity

10.2 W/m·K5.9 BTU/hr·ft·°F
10.5 W/m·K6.1 BTU/hr·ft·°F

Specific Heat Capacity

385 J/kg·K0.09 BTU/lb·°F
440 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

11.3 µm/m·K6.3 µin/in·°F
12.2 µm/m·K6.8 µin/in·°F

Latent Heat of Fusion

290 J/g125 BTU/lb
285 J/g123 BTU/lb

Max Service Temperature (continuous)

650°C1,202 °F
850°C1,562 °F

Same in both: Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

1.3 % IACS
—

Electrical Resistivity

1.3×10⁻⁶ Ω·m51.2 µΩ·in
1.25×10⁻⁶ Ω·m49.2 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.08 V
-0.15 V

Corrosion Resistance

86 / 100
80 / 100

Manufacturability

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

Machinability

22 / 100
12 / 100

Machinability Rating (AISI 1212 = 100 %)

12%
8%

Weldability

55 / 100
25 / 100

Formability (cold)

15 / 100
5 / 100

Castability

60 / 100
65 / 100

Polishability

65 / 100
60 / 100

Same in both: Brazeability / Solderability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

150 MJ/kg64,488 BTU/lb
215 MJ/kg92,433 BTU/lb

Embodied Carbon (primary production)

12.5 kg CO₂/kg
14.5 kg CO₂/kg

Embodied Water

300 L/kg35.9 gal/lb
260 L/kg31.2 gal/lb

Typical Recycled Content

40%
30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

62 kN·m/kg
135 kN·m/kg

Specific Stiffness (E / density)

22.9 MN·m/kg
25.1 MN·m/kg

Modulus of Resilience

299 kJ/m³
1,484 kJ/m³

Thermal Diffusivity

3 mm²/s
2.9 mm²/s

Thermal Shock Resistance Index

2
5

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 scaleCW-12MWIN-939

Manufacturing and finishing

CapabilityCW-12MWIN-939
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

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

CW-12MW vs IN-939 — frequently asked

Is IN-939 stronger than CW-12MW?

Yes. IN-939 has a typical yield strength of 780 MPa (113 ksi) against 350 MPa (50.8 ksi) for CW-12MW — about 123% more. Tensile strength is 1,100 MPa (160 ksi) vs 550 MPa (79.8 ksi).

Which is cheaper, CW-12MW or IN-939?

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 is easier to machine, CW-12MW or IN-939?

CW-12MW. Its machinability rates poor (22/100) against not recommended (12/100) for IN-939; for welding the order is CW-12MW first (good, 55/100) then IN-939 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in CW-12MW and IN-939 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.