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Stainless Steel 1.3940 vs CE8MN

Stainless Steel · grade comparison

Stainless Steel 1.3940 and CE8MN are both stainless steel grades. CE8MN is the stronger of the two: yield strength 500 MPa (72.5 ksi) against 250 MPa (36.3 ksi) for 1.3940, about 100% more; tensile strength follows at 720 MPa (104 ksi) vs 530 MPa (76.9 ksi). In exchange, 1.3940 is the more ductile: elongation 55% versus 30% for CE8MN, and CE8MN is harder (210 HB vs 140 HB). 1.3940 runs hotter in service (425°C vs 315°C continuous). On the shop floor, 1.3940 welds better (excellent vs good).

1.3940Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

CE8MNChoose it when strength drives the design.

1.3940 vs CE8MN: properties

1.3940CE8MN

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

193 GPa28 Msi
195 GPa28.3 Msi

Shear Modulus

77 GPa11.2 Msi
76 GPa11 Msi

Bulk Modulus

160 GPa23.2 Msi
162 GPa23.5 Msi

Tensile Strength (Ultimate)

530 MPa76.9 ksi
720 MPa104 ksi

Yield Strength (0.2% offset)

250 MPa36.3 ksi
500 MPa72.5 ksi

Elongation at Break

55%
30%

Reduction in Area

60%
40%

Shear Strength

330 MPa47.9 ksi
430 MPa62.4 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
300 MPa43.5 ksi

Fracture Toughness (K_IC)

200 MPa·√m182 ksi·√in
100 MPa·√m91 ksi·√in

Charpy V-Notch Impact (RT)

130 J95.9 ft·lbf
80 J59 ft·lbf

Hardness, Brinell

140 HB
210 HB

Hardness, Rockwell B

77 HRB
—

Compressive Strength

—
500 MPa72.5 ksi

Hardness, Rockwell C

—
20 HRC

Same in both: Poisson's Ratio 0.3

Physical

Density and transition temperatures.

Same in both: Density 7.75 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,400°C2,552 °F · Liquidus Temperature 1,450°C2,642 °F

Thermal

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

Thermal Conductivity

16.2 W/m·K9.4 BTU/hr·ft·°F
15 W/m·K8.7 BTU/hr·ft·°F

Specific Heat Capacity

500 J/kg·K0.12 BTU/lb·°F
490 J/kg·K0.12 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

16.5 µm/m·K9.2 µin/in·°F
13 µm/m·K7.2 µin/in·°F

Max Service Temperature (continuous)

425°C797 °F
315°C599 °F

Min Service Temperature

-196°C-321 °F
-50°C-58 °F

Same in both: Latent Heat of Fusion 270 J/g116 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

2.3 % IACS
2.2 % IACS

Electrical Resistivity

7.5×10⁻⁷ Ω·m29.5 µΩ·in
8×10⁻⁷ Ω·m31.5 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.08 V
-0.2 V

Corrosion Resistance

63 / 100
72 / 100

Manufacturability

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

Machinability

40 / 100
32 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
30%

Weldability

88 / 100
65 / 100

Formability (cold)

35 / 100
30 / 100

Castability

75 / 100
65 / 100

Brazeability / Solderability

60 / 100
35 / 100

Polishability

62 / 100
65 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

53 MJ/kg22,786 BTU/lb
60 MJ/kg25,795 BTU/lb

Embodied Carbon (primary production)

4.3 kg CO₂/kg
5 kg CO₂/kg

Embodied Water

130 L/kg15.6 gal/lb
250 L/kg30 gal/lb

Typical Recycled Content

75%
80%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

68 kN·m/kg
93 kN·m/kg

Specific Stiffness (E / density)

24.9 MN·m/kg
25.2 MN·m/kg

Modulus of Resilience

162 kJ/m³
641 kJ/m³

Thermal Diffusivity

4.2 mm²/s
3.9 mm²/s

Thermal Shock Resistance Index

3
4

Strength versus weight

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

3005007001,0001,5002,0007.27.47.67.888.2Density (g/cm³)Yield strength (MPa) — log scaleCE8MN1.3940

Manufacturing and finishing

Capability1.3940CE8MN
Default condition——
Relative cost$$$ Premium$$$ Premium
Min. machined wall——
Best machined surface——

Both take the same 7 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Pickling, Plasma Spray, Silver Plating.

1.3940 vs CE8MN — frequently asked

Is CE8MN stronger than 1.3940?

Yes. CE8MN has a typical yield strength of 500 MPa (72.5 ksi) against 250 MPa (36.3 ksi) for 1.3940 — about 100% more. Tensile strength is 720 MPa (104 ksi) vs 530 MPa (76.9 ksi).

Which is cheaper, 1.3940 or CE8MN?

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

Which is easier to machine, 1.3940 or CE8MN?

1.3940. Its machinability rates fair (40/100) against poor (32/100) for CE8MN; for welding the order is 1.3940 first (excellent, 88/100) then CE8MN (good, 65/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 1.3940 and CE8MN 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.