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Steel A372 Grade L N+T vs A372 Grade L QT-40-44HRC

Steel · A372 Grade L temper comparison

A372 Grade L N+T and A372 Grade L QT-40-44HRC are two conditions of the same steel grade, A372 Grade L: N+T (normalized and tempered) versus QT-40-44HRC. The chemistry is identical, so every difference below comes from the condition. A372 Grade L QT-40-44HRC is the stronger of the two: yield strength 1,170 MPa (170 ksi) against 520 MPa (75.4 ksi) for A372 Grade L N+T, about 125% more; tensile strength follows at 1,310 MPa (190 ksi) vs 760 MPa (110 ksi). In exchange, A372 Grade L N+T is the more ductile: elongation 20% versus 13% for A372 Grade L QT-40-44HRC, and A372 Grade L QT-40-44HRC is harder (401 HB vs 229 HB). On the shop floor, A372 Grade L N+T welds better (fair vs poor).

A372 Grade L N+TChoose it when the part is bent, formed or impact-loaded, or when it will be welded.

A372 Grade L QT-40-44HRCChoose it when strength drives the design.

A372 Grade L N+T vs A372 Grade L QT-40-44HRC: properties

A372 Grade L N+TA372 Grade L QT-40-44HRC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

760 MPa110 ksi
1,310 MPa190 ksi

Yield Strength (0.2% offset)

520 MPa75.4 ksi
1,170 MPa170 ksi

Elongation at Break

20%
13%

Reduction in Area

52%
40%

Fatigue Strength (Endurance Limit)

350 MPa50.8 ksi
580 MPa84.1 ksi

Fracture Toughness (K_IC)

70 MPa·√m63.7 ksi·√in
55 MPa·√m50.1 ksi·√in

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
20 J14.8 ft·lbf

Hardness, Brinell

229 HB
401 HB

Hardness, Rockwell C

20 HRC
42 HRC

Hardness, Vickers

240 HV
420 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 · Compressive Strength 1,050 MPa152 ksi · Shear Strength 700 MPa102 ksi

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,416°C2,581 °F · Liquidus Temperature 1,470°C2,678 °F

Thermal

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

Same in both: Thermal Conductivity 42 W/m·K24.3 BTU/hr·ft·°F · Specific Heat Capacity 473 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 250 J/g107 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -40°C-40 °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 Rating (AISI 1212 = 100 %)

60%
30%

Weldability

35 / 100
15 / 100

Same in both: Machinability 38 / 100 · Formability (cold) 12 / 100 · Brazeability / Solderability 45 / 100 · Polishability 68 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 32 MJ/kg13,758 BTU/lb · Embodied Carbon (primary production) 2.3 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 L

A372 Grade L N+T vs A372 Grade L QT-40-44HRC — frequently asked

Is A372 Grade L QT-40-44HRC stronger than A372 Grade L N+T?

Yes. A372 Grade L QT-40-44HRC has a typical yield strength of 1,170 MPa (170 ksi) against 520 MPa (75.4 ksi) for A372 Grade L N+T — about 125% more. Tensile strength is 1,310 MPa (190 ksi) vs 760 MPa (110 ksi).

Which condition does FabDigit quote by default, N+T or QT-40-44HRC?

QT-HS is the default A372 Grade L condition in the FabDigit quote flow (neither N+T nor QT-40-44HRC). 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 welds better, A372 Grade L N+T or A372 Grade L QT-40-44HRC?

A372 Grade L N+T. Its weldability rates fair (35/100) against poor (15/100) for A372 Grade L QT-40-44HRC.

Ready to make it?

Upload a CAD file and FabDigit prices the part in A372 Grade L N+T and A372 Grade L QT-40-44HRC 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.