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Steel A372 Grade M-A vs A372 Grade M-N

Steel · A372 Grade M temper comparison

A372 Grade M-A and A372 Grade M-N are two conditions of the same steel grade, A372 Grade M: A (solution annealed) versus N (normalized). The chemistry is identical, so every difference below comes from the condition. A372 Grade M-N is the stronger of the two: yield strength 530 MPa (76.9 ksi) against 400 MPa (58 ksi) for A372 Grade M-A, about 33% more; tensile strength follows at 830 MPa (120 ksi) vs 660 MPa (95.7 ksi). In exchange, A372 Grade M-A is the more ductile: elongation 24% versus 20% for A372 Grade M-N, and A372 Grade M-N is harder (248 HB vs 197 HB). On the shop floor, A372 Grade M-A machines more easily (good vs fair) and A372 Grade M-A welds better (45 vs 35 out of 100).

A372 Grade M-AChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

A372 Grade M-NChoose it when strength drives the design.

A372 Grade M-A vs A372 Grade M-N: properties

A372 Grade M-AA372 Grade M-N

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

660 MPa95.7 ksi
830 MPa120 ksi

Yield Strength (0.2% offset)

400 MPa58 ksi
530 MPa76.9 ksi

Elongation at Break

24%
20%

Reduction in Area

55%
48%

Compressive Strength

725 MPa105 ksi
530 MPa76.9 ksi

Shear Strength

520 MPa75.4 ksi
500 MPa72.5 ksi

Fatigue Strength (Endurance Limit)

385 MPa55.8 ksi
370 MPa53.7 ksi

Fracture Toughness (K_IC)

100 MPa·√m91 ksi·√in
85 MPa·√m77.4 ksi·√in

Charpy V-Notch Impact (RT)

45 J33.2 ft·lbf
35 J25.8 ft·lbf

Hardness, Brinell

197 HB
248 HB

Hardness, Rockwell C

26 HRC
24 HRC

Hardness, Vickers

275 HV
260 HV

Same in both: Elastic (Young's) Modulus 205 GPa29.7 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) 1,425°C2,597 °F · Liquidus Temperature 1,495°C2,723 °F

Thermal

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

Thermal Conductivity

42 W/m·K24.3 BTU/hr·ft·°F
43 W/m·K24.8 BTU/hr·ft·°F

Max Service Temperature (continuous)

400°C752 °F
425°C797 °F

Same in both: Specific Heat Capacity 475 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 -30°C-22 °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) -0.61 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

58 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
52%

Weldability

45 / 100
35 / 100

Formability (cold)

40 / 100
30 / 100

Same in both: Brazeability / Solderability 45 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Carbon (primary production) 2.2 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 30%

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 scaleA372 Grade M

A372 Grade M-A vs A372 Grade M-N — frequently asked

Is A372 Grade M-N stronger than A372 Grade M-A?

Yes. A372 Grade M-N has a typical yield strength of 530 MPa (76.9 ksi) against 400 MPa (58 ksi) for A372 Grade M-A — about 33% more. Tensile strength is 830 MPa (120 ksi) vs 660 MPa (95.7 ksi).

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

QT-CL100 is the default A372 Grade M 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, A372 Grade M-A or A372 Grade M-N?

A372 Grade M-A. Its machinability rates good (58/100) against fair (45/100) for A372 Grade M-N; for welding the order is A372 Grade M-A first (fair, 45/100) then A372 Grade M-N (fair, 35/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A372 Grade M-A and A372 Grade M-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.