Stainless Steel 1.4122 +A vs 1.4122 +QT750
Stainless Steel · 1.4122 temper comparison
1.4122 +A and 1.4122 +QT750 are two conditions of the same stainless steel grade, 1.4122: +A (annealed) versus +QT750 (quenched and tempered, Rm 750–950 MPa). The chemistry is identical, so every difference below comes from the condition. 1.4122 +QT750 is the stronger of the two: yield strength 620 MPa (89.9 ksi) against 460 MPa (66.7 ksi) for 1.4122 +A, about 35% more; tensile strength follows at 850 MPa (123 ksi) vs 780 MPa (113 ksi). In exchange, 1.4122 +A is the more ductile: elongation 18% versus 14% for 1.4122 +QT750, and 1.4122 +QT750 is harder (265 HB vs 240 HB). 1.4122 +QT750 runs hotter in service (500°C vs 400°C continuous). On the shop floor, 1.4122 +A machines more easily (45 vs 35 out of 100).
1.4122 +AChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
1.4122 +QT750Choose it when strength drives the design, or when the part sees heat.
1.4122 +A vs 1.4122 +QT750: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all stainless 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 stainless 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
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 216 GPa31.3 Msi · Shear Modulus 83 GPa12 Msi · Bulk Modulus 163 GPa23.6 Msi · Poisson's Ratio 0.29 · Reduction in Area 45% · Compressive Strength 470 MPa68.2 ksi
Physical
Density and transition temperatures.
Same in both: Density 7.7 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.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 30 W/m·K17.3 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.5 µm/m·K5.8 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.9 % IACS · Electrical Resistivity 6×10⁻⁷ Ω·m23.6 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.3 V
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 75 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 55 MJ/kg23,646 BTU/lb · Embodied Carbon (primary production) 4.8 kg CO₂/kg · Embodied Water 110 L/kg13.2 gal/lb · Typical Recycled Content 50%
Strength versus weight
Yield strength against density for every stainless steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
1.4122 +A vs 1.4122 +QT750 — frequently asked
Is 1.4122 +QT750 stronger than 1.4122 +A?
Yes. 1.4122 +QT750 has a typical yield strength of 620 MPa (89.9 ksi) against 460 MPa (66.7 ksi) for 1.4122 +A — about 35% more. Tensile strength is 850 MPa (123 ksi) vs 780 MPa (113 ksi).
Which condition does FabDigit quote by default, +A or +QT750?
+A is the default 1.4122 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, 1.4122 +A or 1.4122 +QT750?
1.4122 +A, by a small margin. Both rate fair for machinability — 45/100 against 35/100 for 1.4122 +QT750.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1.4122 +A and 1.4122 +QT750 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.