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Nickel Alloy CY-40 vs M25S

Nickel Alloy · grade comparison

Nickel Alloy CY-40 and M25S are both nickel alloy grades. M25S is the stronger of the two: yield strength 550 MPa (79.8 ksi) against 245 MPa (35.5 ksi) for CY-40, about 124% more; tensile strength follows at 760 MPa (110 ksi) vs 520 MPa (75.4 ksi). In exchange, CY-40 is the more ductile: elongation 38% versus 1.5% for M25S, and M25S is harder (320 HB vs 145 HB). CY-40 is stiffer (200 GPa vs 172 GPa) and CY-40 runs hotter in service (1,000°C vs 450°C continuous). On the shop floor, CY-40 machines more easily (poor vs not recommended) and CY-40 welds better (good vs not recommended).

CY-40Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

M25SChoose it when strength drives the design.

CY-40 vs M25S: properties

CY-40M25S

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
172 GPa24.9 Msi

Shear Modulus

76 GPa11 Msi
66 GPa9.6 Msi

Bulk Modulus

175 GPa25.4 Msi
145 GPa21 Msi

Tensile Strength (Ultimate)

520 MPa75.4 ksi
760 MPa110 ksi

Yield Strength (0.2% offset)

245 MPa35.5 ksi
550 MPa79.8 ksi

Elongation at Break

38%
1.5%

Reduction in Area

40%
2%

Compressive Strength

250 MPa36.3 ksi
1,400 MPa203 ksi

Shear Strength

350 MPa50.8 ksi
460 MPa66.7 ksi

Fatigue Strength (Endurance Limit)

215 MPa31.2 ksi
250 MPa36.3 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
25 MPa·√m22.8 ksi·√in

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
5 J3.7 ft·lbf

Hardness, Brinell

145 HB
320 HB

Hardness, Rockwell B

78 HRB
—

Hardness, Vickers

152 HV
336 HV

Hardness, Rockwell C

—
34 HRC

Same in both: Poisson's Ratio 0.31

Physical

Density and transition temperatures.

Density

8.45 g/cm³0.31 lb/in³
8.36 g/cm³0.3 lb/in³

Melting Point (Solidus)

1,354°C2,469 °F
1,010°C1,850 °F

Liquidus Temperature

1,413°C2,575 °F
1,080°C1,976 °F

Thermal

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

Thermal Conductivity

14.8 W/m·K8.6 BTU/hr·ft·°F
18 W/m·K10.4 BTU/hr·ft·°F

Specific Heat Capacity

444 J/kg·K0.11 BTU/lb·°F
430 J/kg·K0.1 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

13.3 µm/m·K7.4 µin/in·°F
13 µm/m·K7.2 µin/in·°F

Latent Heat of Fusion

290 J/g125 BTU/lb
—

Max Service Temperature (continuous)

1,000°C1,832 °F
450°C842 °F

Min Service Temperature

-196°C-321 °F
—

Electrical

Conductivity and insulation.

Electrical Conductivity

1.7 % IACS
2.3 % IACS

Electrical Resistivity

1.03×10⁻⁶ Ω·m40.6 µΩ·in
7.5×10⁻⁷ Ω·m29.5 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.18 V
-0.15 V

Corrosion Resistance

76 / 100
75 / 100

Manufacturability

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

Machinability

28 / 100
12 / 100

Machinability Rating (AISI 1212 = 100 %)

15%
10%

Weldability

60 / 100
12 / 100

Formability (cold)

20 / 100
3 / 100

Castability

58 / 100
78 / 100

Brazeability / Solderability

55 / 100
40 / 100

Polishability

60 / 100
70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

150 MJ/kg64,488 BTU/lb
130 MJ/kg55,890 BTU/lb

Embodied Carbon (primary production)

12 kg CO₂/kg
11 kg CO₂/kg

Embodied Water

350 L/kg41.9 gal/lb
300 L/kg35.9 gal/lb

Typical Recycled Content

45%
40%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

62 kN·m/kg
91 kN·m/kg

Specific Stiffness (E / density)

23.7 MN·m/kg
20.6 MN·m/kg

Modulus of Resilience

150 kJ/m³
879 kJ/m³

Thermal Diffusivity

3.9 mm²/s
5 mm²/s

Thermal Shock Resistance Index

3
6

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 scaleCY-40M25S

Manufacturing and finishing

CapabilityCY-40M25S
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

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

CY-40 vs M25S — frequently asked

Is M25S stronger than CY-40?

Yes. M25S has a typical yield strength of 550 MPa (79.8 ksi) against 245 MPa (35.5 ksi) for CY-40 — about 124% more. Tensile strength is 760 MPa (110 ksi) vs 520 MPa (75.4 ksi).

Which is cheaper, CY-40 or M25S?

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, CY-40 or M25S?

CY-40. Its machinability rates poor (28/100) against not recommended (12/100) for M25S; for welding the order is CY-40 first (good, 60/100) then M25S (not recommended, 12/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in CY-40 and M25S 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.