Steel A372 Gr E-A vs A372 Gr E CL55-QT
Steel · A372 Gr E temper comparison
A372 Gr E-A and A372 Gr E CL55-QT are two conditions of the same steel grade, A372 Gr E: A (solution annealed) versus CL55-QT (class 55). The chemistry is identical, so every difference below comes from the condition. A372 Gr E CL55-QT is the stronger of the two: yield strength 420 MPa (60.9 ksi) against 370 MPa (53.7 ksi) for A372 Gr E-A, about 14% more; tensile strength follows at 630 MPa (91.4 ksi) vs 590 MPa (85.6 ksi). A372 Gr E CL55-QT is harder — 187 HB against 170 HB for A372 Gr E-A — which matters for wear surfaces and threads. On the shop floor, A372 Gr E-A forms better (fair vs poor).
A372 Gr E CL55-QTChoose it when strength drives the design, or when surface hardness matters.
A372 Gr E-A vs A372 Gr E CL55-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 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Hardness, Rockwell C 20 HRC
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 1,500°C2,732 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 42 W/m·K24.3 BTU/hr·ft·°F · Specific Heat Capacity 470 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 · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 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) -0.62 V · Corrosion Resistance 13 / 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: Brazeability / Solderability 45 / 100 · Polishability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 34 MJ/kg14,617 BTU/lb · Embodied Carbon (primary production) 2.3 kg CO₂/kg · Embodied Water 60 L/kg7.2 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.
A372 Gr E-A vs A372 Gr E CL55-QT — frequently asked
Is A372 Gr E CL55-QT stronger than A372 Gr E-A?
Yes. A372 Gr E CL55-QT has a typical yield strength of 420 MPa (60.9 ksi) against 370 MPa (53.7 ksi) for A372 Gr E-A — about 14% more. Tensile strength is 630 MPa (91.4 ksi) vs 590 MPa (85.6 ksi).
Which condition does FabDigit quote by default, A or CL55-QT?
CL70-QT is the default A372 Gr E condition in the FabDigit quote flow (neither A nor CL55-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 welds better, A372 Gr E-A or A372 Gr E CL55-QT?
A372 Gr E-A. Its weldability rates good (55/100) against fair (50/100) for A372 Gr E CL55-QT.
Ready to make it?
Upload a CAD file and FabDigit prices the part in A372 Gr E-A and A372 Gr E CL55-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.