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Steel A372 Grade M-N vs A372 Grade M QT-CL85

Steel · A372 Grade M temper comparison

A372 Grade M-N and A372 Grade M QT-CL85 are two conditions of the same steel grade, A372 Grade M: N (normalized) versus QT-CL85 (class 85). The chemistry is identical, so every difference below comes from the condition. A372 Grade M QT-CL85 is the stronger of the two: yield strength 620 MPa (89.9 ksi) against 530 MPa (76.9 ksi) for A372 Grade M-N, about 17% more. In exchange, A372 Grade M-N is the more ductile: elongation 20% versus 18% for A372 Grade M QT-CL85, and A372 Grade M-N is harder (248 HB vs 235 HB).

A372 Grade M-NChoose it when the part is bent, formed or impact-loaded.

A372 Grade M QT-CL85Choose it when strength drives the design.

A372 Grade M-N vs A372 Grade M QT-CL85: properties

A372 Grade M-NA372 Grade M QT-CL85

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

830 MPa120 ksi
790 MPa115 ksi

Yield Strength (0.2% offset)

530 MPa76.9 ksi
620 MPa89.9 ksi

Elongation at Break

20%
18%

Reduction in Area

48%
50%

Compressive Strength

530 MPa76.9 ksi
725 MPa105 ksi

Shear Strength

500 MPa72.5 ksi
480 MPa69.6 ksi

Fatigue Strength (Endurance Limit)

370 MPa53.7 ksi
350 MPa50.8 ksi

Fracture Toughness (K_IC)

85 MPa·√m77.4 ksi·√in
115 MPa·√m105 ksi·√in

Charpy V-Notch Impact (RT)

35 J25.8 ft·lbf
60 J44.3 ft·lbf

Hardness, Brinell

248 HB
235 HB

Hardness, Rockwell C

24 HRC
21 HRC

Hardness, Vickers

260 HV
245 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

43 W/m·K24.8 BTU/hr·ft·°F
42 W/m·K24.3 BTU/hr·ft·°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 · Max Service Temperature (continuous) 425°C797 °F · 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

45 / 100
48 / 100

Machinability Rating (AISI 1212 = 100 %)

52%
55%

Weldability

35 / 100
34 / 100

Formability (cold)

30 / 100
26 / 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-N vs A372 Grade M QT-CL85 — frequently asked

Is A372 Grade M QT-CL85 stronger than A372 Grade M-N?

Yes. A372 Grade M QT-CL85 has a typical yield strength of 620 MPa (89.9 ksi) against 530 MPa (76.9 ksi) for A372 Grade M-N — about 17% more. Tensile strength is 790 MPa (115 ksi) vs 830 MPa (120 ksi).

Which condition does FabDigit quote by default, N or QT-CL85?

QT-CL100 is the default A372 Grade M condition in the FabDigit quote flow (neither N nor QT-CL85). 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.

When should I choose A372 Grade M-N over A372 Grade M QT-CL85?

Pick A372 Grade M-N when the part is bent, formed or impact-loaded. Pick A372 Grade M QT-CL85 when strength drives the design.

Ready to make it?

Upload a CAD file and FabDigit prices the part in A372 Grade M-N and A372 Grade M QT-CL85 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.