Steel 1120-A vs 1120 CARB-QT
Steel · 1120 temper comparison
1120-A and 1120 CARB-QT are two conditions of the same steel grade, 1120: A (solution annealed) versus CARB-QT (carburized, Quenched and Tempered). The chemistry is identical, so every difference below comes from the condition. 1120 CARB-QT is the stronger of the two: yield strength 400 MPa (58 ksi) against 220 MPa (31.9 ksi) for 1120-A, about 82% more; tensile strength follows at 620 MPa (89.9 ksi) vs 395 MPa (57.3 ksi). In exchange, 1120-A is the more ductile: elongation 30% versus 14% for 1120 CARB-QT, and 1120 CARB-QT is harder (200 HB vs 111 HB). On the shop floor, 1120-A machines more easily (good vs poor) and 1120-A welds better (fair vs poor).
1120-AChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
1120 CARB-QTChoose it when strength drives the design.
1120-A vs 1120 CARB-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
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 140 GPa20.3 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) 1,420°C2,588 °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 486 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.7 µm/m·K6.5 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -20°C-4 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Same in both: Electrical Resistivity 1.6×10⁻⁷ Ω·m6.3 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V · Corrosion Resistance 10 / 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 60 / 100 · Polishability 40 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 2 kg CO₂/kg · Embodied Water 50 L/kg6 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.
1120-A vs 1120 CARB-QT — frequently asked
Is 1120 CARB-QT stronger than 1120-A?
Yes. 1120 CARB-QT has a typical yield strength of 400 MPa (58 ksi) against 220 MPa (31.9 ksi) for 1120-A — about 82% more. Tensile strength is 620 MPa (89.9 ksi) vs 395 MPa (57.3 ksi).
Which condition does FabDigit quote by default, A or CARB-QT?
CD is the default 1120 condition in the FabDigit quote flow (neither A nor CARB-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, 1120-A or 1120 CARB-QT?
1120-A. Its machinability rates good (68/100) against poor (25/100) for 1120 CARB-QT; for welding the order is 1120-A first (fair, 48/100) then 1120 CARB-QT (poor, 15/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1120-A and 1120 CARB-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.