Steel A372 Grade A-A vs A372 Grade A-QT
Steel · A372 Grade A temper comparison
A372 Grade A-A and A372 Grade A-QT are two conditions of the same steel grade, A372 Grade A: A (solution annealed) versus QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. A372 Grade A-QT is the stronger of the two: yield strength 420 MPa (60.9 ksi) against 250 MPa (36.3 ksi) for A372 Grade A-A, about 68% more; tensile strength follows at 600 MPa (87 ksi) vs 460 MPa (66.7 ksi). In exchange, A372 Grade A-A is the more ductile: elongation 32% versus 23% for A372 Grade A-QT, and A372 Grade A-QT is harder (185 HB vs 130 HB).
A372 Grade A-AChoose it when the part is bent, formed or impact-loaded.
A372 Grade A-QTChoose it when strength drives the design.
A372 Grade A-A vs A372 Grade A-QT: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 79 GPa11.5 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 1,510°C2,750 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Same in both: Specific Heat Capacity 470 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 250 J/g107 BTU/lb · Max Service Temperature (continuous) 425°C797 °F · Min Service Temperature -29°C-20 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
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
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Castability 50 / 100 · Brazeability / Solderability 65 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 26 MJ/kg11,178 BTU/lb · Embodied Carbon (primary production) 2 kg CO₂/kg · Embodied Water 45 L/kg5.4 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.
A372 Grade A-A vs A372 Grade A-QT — frequently asked
Is A372 Grade A-QT stronger than A372 Grade A-A?
Yes. A372 Grade A-QT has a typical yield strength of 420 MPa (60.9 ksi) against 250 MPa (36.3 ksi) for A372 Grade A-A — about 68% more. Tensile strength is 600 MPa (87 ksi) vs 460 MPa (66.7 ksi).
Which condition does FabDigit quote by default, A or QT?
N is the default A372 Grade A condition in the FabDigit quote flow (neither A nor QT). 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 A-A or A372 Grade A-QT?
A372 Grade A-A, by a small margin. Both rate good for machinability — 62/100 against 55/100 for A372 Grade A-QT; for welding the order is A372 Grade A-A first (very good, 75/100) then A372 Grade A-QT (very good, 70/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in A372 Grade A-A and A372 Grade A-QT 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.