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Steel 18MnMo4-5 +A vs 18MnMo4-5 +N

Steel · 18MnMo4-5 temper comparison

18MnMo4-5 +A and 18MnMo4-5 +N are two conditions of the same steel grade, 18MnMo4-5: +A (annealed) versus +N (normalized). The chemistry is identical, so every difference below comes from the condition. 18MnMo4-5 +N is the stronger of the two: yield strength 390 MPa (56.6 ksi) against 300 MPa (43.5 ksi) for 18MnMo4-5 +A, about 30% more; tensile strength follows at 620 MPa (89.9 ksi) vs 520 MPa (75.4 ksi). In exchange, 18MnMo4-5 +A is the more ductile: elongation 26% versus 20% for 18MnMo4-5 +N, and 18MnMo4-5 +N is harder (190 HB vs 155 HB).

18MnMo4-5 +AChoose it when the part is bent, formed or impact-loaded.

18MnMo4-5 +NChoose it when strength drives the design.

18MnMo4-5 +A vs 18MnMo4-5 +N: properties

18MnMo4-5 +A18MnMo4-5 +N

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

520 MPa75.4 ksi
620 MPa89.9 ksi

Yield Strength (0.2% offset)

300 MPa43.5 ksi
390 MPa56.6 ksi

Elongation at Break

26%
20%

Reduction in Area

60%
52%

Compressive Strength

400 MPa58 ksi
390 MPa56.6 ksi

Shear Strength

375 MPa54.4 ksi
380 MPa55.1 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
285 MPa41.3 ksi

Fracture Toughness (K_IC)

120 MPa·√m109 ksi·√in
110 MPa·√m100 ksi·√in

Charpy V-Notch Impact (RT)

90 J66.4 ft·lbf
100 J73.8 ft·lbf

Hardness, Brinell

155 HB
190 HB

Hardness, Rockwell B

82 HRB
91 HRB

Hardness, Vickers

195 HV
200 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 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)

480°C896 °F
470°C878 °F

Same in both: Thermal Conductivity 42 W/m·K24.3 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 7.8 % IACS · Electrical Resistivity 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) -0.6 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

62 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
60%

Formability (cold)

60 / 100
52 / 100

Same in both: Weldability 70 / 100 · Castability 40 / 100 · Brazeability / Solderability 55 / 100 · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 28 MJ/kg12,038 BTU/lb · Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 50 L/kg6 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 scale18MnMo4-5

18MnMo4-5 +A vs 18MnMo4-5 +N — frequently asked

Is 18MnMo4-5 +N stronger than 18MnMo4-5 +A?

Yes. 18MnMo4-5 +N has a typical yield strength of 390 MPa (56.6 ksi) against 300 MPa (43.5 ksi) for 18MnMo4-5 +A — about 30% more. Tensile strength is 620 MPa (89.9 ksi) vs 520 MPa (75.4 ksi).

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

+NT is the default 18MnMo4-5 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, 18MnMo4-5 +A or 18MnMo4-5 +N?

18MnMo4-5 +A, by a small margin. Both rate good for machinability — 62/100 against 55/100 for 18MnMo4-5 +N.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 18MnMo4-5 +A and 18MnMo4-5 +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.