Steel A372 Grade J-ANN vs A372 Grade J QT-CL70
Steel · A372 Grade J temper comparison
A372 Grade J-ANN and A372 Grade J QT-CL70 are two conditions of the same steel grade, A372 Grade J: ANN (annealed) versus QT-CL70 (class 70). The chemistry is identical, so every difference below comes from the condition. A372 Grade J QT-CL70 is the stronger of the two: yield strength 520 MPa (75.4 ksi) against 370 MPa (53.7 ksi) for A372 Grade J-ANN, about 41% more; tensile strength follows at 720 MPa (104 ksi) vs 620 MPa (89.9 ksi). In exchange, A372 Grade J-ANN is the more ductile: elongation 26% versus 20% for A372 Grade J QT-CL70, and A372 Grade J QT-CL70 is harder (215 HB vs 187 HB). On the shop floor, A372 Grade J-ANN welds better (45 vs 35 out of 100).
A372 Grade J-ANNChoose it when the part is bent, formed or impact-loaded, or when it will be welded.
A372 Grade J QT-CL70Choose it when strength drives the design.
A372 Grade J-ANN vs A372 Grade J QT-CL70: 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.
A372 Grade J-ANNA372 Grade J QT-CL70
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Charpy V-Notch Impact (RT)
Hardness, Brinell
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 520 MPa75.4 ksi · Shear Strength 440 MPa63.8 ksi · Fatigue Strength (Endurance Limit) 330 MPa47.9 ksi · Fracture Toughness (K_IC) 110 MPa·√m100 ksi·√in · Hardness, Rockwell C 18 HRC · Hardness, Vickers 225 HV
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 1,490°C2,714 °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 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 · Max Service Temperature (continuous) 400°C752 °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 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: Castability 40 / 100 · Brazeability / Solderability 50 / 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) 2.3 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 Grade J-ANN vs A372 Grade J QT-CL70 — frequently asked
Is A372 Grade J QT-CL70 stronger than A372 Grade J-ANN?
Yes. A372 Grade J QT-CL70 has a typical yield strength of 520 MPa (75.4 ksi) against 370 MPa (53.7 ksi) for A372 Grade J-ANN — about 41% more. Tensile strength is 720 MPa (104 ksi) vs 620 MPa (89.9 ksi).
Which condition does FabDigit quote by default, ANN or QT-CL70?
QT-CL70 is the default A372 Grade J condition in the FabDigit quote flow. 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 J-ANN or A372 Grade J QT-CL70?
A372 Grade J-ANN, by a small margin. Both rate good for machinability — 64/100 against 55/100 for A372 Grade J QT-CL70; for welding the order is A372 Grade J-ANN first (fair, 45/100) then A372 Grade J QT-CL70 (fair, 35/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in A372 Grade J-ANN and A372 Grade J QT-CL70 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.