Steel 12CrNi3A-A vs 12CrNi3A-QT
Steel · 12CrNi3A temper comparison
12CrNi3A-A and 12CrNi3A-QT are two conditions of the same steel grade, 12CrNi3A: A (solution annealed) versus QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. 12CrNi3A-QT is the stronger of the two: yield strength 785 MPa (114 ksi) against 390 MPa (56.6 ksi) for 12CrNi3A-A, about 101% more; tensile strength follows at 980 MPa (142 ksi) vs 620 MPa (89.9 ksi). In exchange, 12CrNi3A-A is the more ductile: elongation 22% versus 13% for 12CrNi3A-QT, and 12CrNi3A-QT is harder (300 HB vs 190 HB). On the shop floor, 12CrNi3A-A machines more easily (good vs fair) and 12CrNi3A-A welds better (45 vs 35 out of 100).
12CrNi3A-AChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
12CrNi3A-QTChoose it when strength drives the design.
12CrNi3A-A vs 12CrNi3A-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
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 165 GPa23.9 Msi · Poisson's Ratio 0.29 · Compressive Strength 790 MPa115 ksi · Shear Strength 590 MPa85.6 ksi · Fracture Toughness (K_IC) 100 MPa·√m91 ksi·√in · Hardness, Rockwell C 31 HRC · Hardness, Vickers 315 HV
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 1,490°C2,714 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 34 W/m·K19.6 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.8 µm/m·K6.6 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 200°C392 °F · Min Service Temperature -70°C-94 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 5.7 % IACS · Electrical Resistivity 3×10⁻⁷ Ω·m11.8 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 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 55 / 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) 2.4 kg CO₂/kg · Embodied Water 65 L/kg7.8 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.
12CrNi3A-A vs 12CrNi3A-QT — frequently asked
Is 12CrNi3A-QT stronger than 12CrNi3A-A?
Yes. 12CrNi3A-QT has a typical yield strength of 785 MPa (114 ksi) against 390 MPa (56.6 ksi) for 12CrNi3A-A — about 101% more. Tensile strength is 980 MPa (142 ksi) vs 620 MPa (89.9 ksi).
Which condition does FabDigit quote by default, A or QT?
QT is the default 12CrNi3A 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, 12CrNi3A-A or 12CrNi3A-QT?
12CrNi3A-A. Its machinability rates good (55/100) against fair (40/100) for 12CrNi3A-QT; for welding the order is 12CrNi3A-A first (fair, 45/100) then 12CrNi3A-QT (fair, 35/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 12CrNi3A-A and 12CrNi3A-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.