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Steel 18MnMoNi5-5-A vs 18MnMoNi5-5-N

Steel · 18MnMoNi5-5 temper comparison

18MnMoNi5-5-A and 18MnMoNi5-5-N are two conditions of the same steel grade, 18MnMoNi5-5: A (solution annealed) versus N (normalized). 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 320 MPa (46.4 ksi) for 18MnMoNi5-5-A, about 34% more; tensile strength follows at 640 MPa (92.8 ksi) vs 520 MPa (75.4 ksi). In exchange, 18MnMoNi5-5-A is the more ductile: elongation 26% versus 20% for 18MnMoNi5-5-N, and 18MnMoNi5-5-N is harder (200 HB vs 160 HB). On the shop floor, 18MnMoNi5-5-A machines more easily (65 vs 55 out of 100).

18MnMoNi5-5-AChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

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

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

18MnMoNi5-5-A18MnMoNi5-5-N

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

520 MPa75.4 ksi
640 MPa92.8 ksi

Yield Strength (0.2% offset)

320 MPa46.4 ksi
430 MPa62.4 ksi

Elongation at Break

26%
20%

Reduction in Area

62%
55%

Shear Strength

330 MPa47.9 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
285 MPa41.3 ksi

Fracture Toughness (K_IC)

130 MPa·√m118 ksi·√in
110 MPa·√m100 ksi·√in

Charpy V-Notch Impact (RT)

90 J66.4 ft·lbf
70 J51.6 ft·lbf

Hardness, Brinell

160 HB
200 HB

Hardness, Rockwell B

84 HRB
93 HRB

Hardness, Vickers

168 HV
210 HV

Same in both: Elastic (Young's) Modulus 207 GPa30 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 7.85 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.

Thermal Conductivity

42 W/m·K24.3 BTU/hr·ft·°F
41 W/m·K23.7 BTU/hr·ft·°F

Max Service Temperature (continuous)

350°C662 °F
380°C716 °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 270 J/g116 BTU/lb · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

2.15×10⁻⁷ Ω·m8.46 µΩ·in
2.2×10⁻⁷ Ω·m8.66 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

65 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

68%
58%

Weldability

70 / 100
65 / 100

Formability (cold)

55 / 100
42 / 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-A vs 18MnMoNi5-5-N — frequently asked

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

Yes. 18MnMoNi5-5-N has a typical yield strength of 430 MPa (62.4 ksi) against 320 MPa (46.4 ksi) for 18MnMoNi5-5-A — about 34% more. Tensile strength is 640 MPa (92.8 ksi) vs 520 MPa (75.4 ksi).

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

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

18MnMoNi5-5-A, by a small margin. Both rate good for machinability — 65/100 against 55/100 for 18MnMoNi5-5-N; for welding the order is 18MnMoNi5-5-A first (very good, 70/100) then 18MnMoNi5-5-N (good, 65/100).

Ready to make it?

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