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Steel En40B-N vs En40B Nitrided

Steel · En40B temper comparison

En40B-N and En40B Nitrided are two conditions of the same steel grade, En40B: N (normalized) versus Nitrided. The chemistry is identical, so every difference below comes from the condition. En40B Nitrided is the stronger of the two: yield strength 745 MPa (108 ksi) against 540 MPa (78.3 ksi) for En40B-N, about 38% more; tensile strength follows at 930 MPa (135 ksi) vs 800 MPa (116 ksi). In exchange, En40B-N is the more ductile: elongation 17% versus 14% for En40B Nitrided, and En40B Nitrided is harder (277 HB vs 245 HB). On the shop floor, En40B-N machines more easily (fair vs not recommended) and En40B-N welds better (poor vs not recommended).

En40B-NChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

En40B NitridedChoose it when strength drives the design.

En40B-N vs En40B Nitrided: properties

En40B-NEn40B Nitrided

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

800 MPa116 ksi
930 MPa135 ksi

Yield Strength (0.2% offset)

540 MPa78.3 ksi
745 MPa108 ksi

Elongation at Break

17%
14%

Reduction in Area

55%
50%

Compressive Strength

550 MPa79.8 ksi
750 MPa109 ksi

Shear Strength

480 MPa69.6 ksi
560 MPa81.2 ksi

Fatigue Strength (Endurance Limit)

370 MPa53.7 ksi
580 MPa84.1 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
80 MPa·√m72.8 ksi·√in

Charpy V-Notch Impact (RT)

35 J25.8 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

245 HB
277 HB

Hardness, Rockwell C

23 HRC
68 HRC

Hardness, Vickers

257 HV
1,000 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Same in both: Density 7.8 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,480°C2,696 °F

Thermal

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

Thermal Conductivity

35 W/m·K20.2 BTU/hr·ft·°F
34 W/m·K19.6 BTU/hr·ft·°F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 500°C932 °F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

6.8 % IACS
6.6 % IACS

Electrical Resistivity

2.55×10⁻⁷ Ω·m10 µΩ·in
2.6×10⁻⁷ Ω·m10.2 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

15 / 100
28 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V

Manufacturability

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

Machinability

50 / 100
5 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
5%

Weldability

25 / 100
2 / 100

Formability (cold)

25 / 100
20 / 100

Polishability

65 / 100
75 / 100

Same in both: Brazeability / Solderability 40 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 31 MJ/kg13,328 BTU/lb · Embodied Carbon (primary production) 2.2 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 25%

Strength versus weight

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

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleEn40B

En40B-N vs En40B Nitrided — frequently asked

Is En40B Nitrided stronger than En40B-N?

Yes. En40B Nitrided has a typical yield strength of 745 MPa (108 ksi) against 540 MPa (78.3 ksi) for En40B-N — about 38% more. Tensile strength is 930 MPa (135 ksi) vs 800 MPa (116 ksi).

Which condition does FabDigit quote by default, N or Nitrided?

T is the default En40B condition in the FabDigit quote flow (neither N nor Nitrided). The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.

Which is easier to machine, En40B-N or En40B Nitrided?

En40B-N. Its machinability rates fair (50/100) against not recommended (5/100) for En40B Nitrided; for welding the order is En40B-N first (poor, 25/100) then En40B Nitrided (not recommended, 2/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in En40B-N and En40B Nitrided 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.