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Steel 18MnMoNi5-5-N vs 18MnMoNi5-5-NT

Steel · 18MnMoNi5-5 temper comparison

18MnMoNi5-5-N and 18MnMoNi5-5-NT are two conditions of the same steel grade, 18MnMoNi5-5: N (normalized) versus NT (normalized and tempered). The chemistry is identical, so every difference below comes from the condition. 18MnMoNi5-5-N is the stronger of the two: yield strength 430 MPa (62.4 ksi) against 400 MPa (58 ksi) for 18MnMoNi5-5-NT, about 8% more; tensile strength follows at 640 MPa (92.8 ksi) vs 570 MPa (82.7 ksi). In exchange, 18MnMoNi5-5-NT is the more ductile: elongation 23% versus 20% for 18MnMoNi5-5-N, and 18MnMoNi5-5-N is harder (200 HB vs 175 HB).

18MnMoNi5-5-NChoose it when strength drives the design.

18MnMoNi5-5-NTChoose it when the part is bent, formed or impact-loaded.

18MnMoNi5-5-N vs 18MnMoNi5-5-NT: properties

18MnMoNi5-5-N18MnMoNi5-5-NT

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

207 GPa30 Msi
206 GPa29.9 Msi

Tensile Strength (Ultimate)

640 MPa92.8 ksi
570 MPa82.7 ksi

Yield Strength (0.2% offset)

430 MPa62.4 ksi
400 MPa58 ksi

Elongation at Break

20%
23%

Reduction in Area

55%
58%

Shear Strength

400 MPa58 ksi
355 MPa51.5 ksi

Fatigue Strength (Endurance Limit)

285 MPa41.3 ksi
255 MPa37 ksi

Fracture Toughness (K_IC)

110 MPa·√m100 ksi·√in
145 MPa·√m132 ksi·√in

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
110 J81.1 ft·lbf

Hardness, Brinell

200 HB
175 HB

Hardness, Rockwell B

93 HRB
87 HRB

Hardness, Vickers

210 HV
184 HV

Same in both: 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 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,460°C2,660 °F · Liquidus Temperature 1,510°C2,750 °F

Thermal

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

Max Service Temperature (continuous)

380°C716 °F
400°C752 °F

Same in both: Thermal Conductivity 41 W/m·K23.7 BTU/hr·ft·°F · 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 270 J/g116 BTU/lb · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.18×10⁻⁷ Ω·m8.58 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 13 / 100

Manufacturability

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

Machinability

55 / 100
60 / 100

Machinability Rating (AISI 1212 = 100 %)

58%
62%

Weldability

65 / 100
68 / 100

Formability (cold)

42 / 100
52 / 100

Same in both: Brazeability / Solderability 40 / 100 · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Carbon (primary production) 2.3 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 20%

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 scale18MnMoNi5-5

18MnMoNi5-5-N vs 18MnMoNi5-5-NT — frequently asked

Is 18MnMoNi5-5-N stronger than 18MnMoNi5-5-NT?

Yes. 18MnMoNi5-5-N has a typical yield strength of 430 MPa (62.4 ksi) against 400 MPa (58 ksi) for 18MnMoNi5-5-NT — about 8% more. Tensile strength is 640 MPa (92.8 ksi) vs 570 MPa (82.7 ksi).

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

QT is the default 18MnMoNi5-5 condition in the FabDigit quote flow (neither N nor NT). 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, 18MnMoNi5-5-N or 18MnMoNi5-5-NT?

18MnMoNi5-5-NT, by a small margin. Both rate good for machinability — 60/100 against 55/100 for 18MnMoNi5-5-N.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 18MnMoNi5-5-N and 18MnMoNi5-5-NT 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.