Stainless Steel 1.4006 +A vs 1.4006 +QT550
Stainless Steel · 1.4006 temper comparison
1.4006 +A and 1.4006 +QT550 are two conditions of the same stainless steel grade, 1.4006: +A (annealed) versus +QT550 (quenched and tempered to Rm 550–750 MPa). The chemistry is identical, so every difference below comes from the condition. 1.4006 +QT550 is the stronger of the two: yield strength 420 MPa (60.9 ksi) against 300 MPa (43.5 ksi) for 1.4006 +A, about 40% more; tensile strength follows at 620 MPa (89.9 ksi) vs 520 MPa (75.4 ksi). In exchange, 1.4006 +A is the more ductile: elongation 24% versus 19% for 1.4006 +QT550, and 1.4006 +QT550 is harder (190 HB vs 155 HB). On the shop floor, 1.4006 +A welds better (45 vs 35 out of 100).
1.4006 +AChoose it when the part is bent, formed or impact-loaded, or when it will be welded.
1.4006 +QT550Choose it when strength drives the design.
1.4006 +A vs 1.4006 +QT550: 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
Reduction in Area
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 215 GPa31.2 Msi · Shear Modulus 83 GPa12 Msi · Bulk Modulus 166 GPa24.1 Msi · Poisson's Ratio 0.29 · Compressive Strength 300 MPa43.5 ksi
Physical
Density and transition temperatures.
Same in both: Density 7.7 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,480°C2,696 °F · Liquidus Temperature 1,530°C2,786 °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 260 J/g112 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) 45 MJ/kg19,347 BTU/lb · Embodied Carbon (primary production) 3.2 kg CO₂/kg · Embodied Water 220 L/kg26.4 gal/lb · Typical Recycled Content 60%
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.
1.4006 +A vs 1.4006 +QT550 — frequently asked
Is 1.4006 +QT550 stronger than 1.4006 +A?
Yes. 1.4006 +QT550 has a typical yield strength of 420 MPa (60.9 ksi) against 300 MPa (43.5 ksi) for 1.4006 +A — about 40% more. Tensile strength is 620 MPa (89.9 ksi) vs 520 MPa (75.4 ksi).
Which condition does FabDigit quote by default, +A or +QT550?
+A is the default 1.4006 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 welds better, 1.4006 +A or 1.4006 +QT550?
1.4006 +A. Its weldability rates fair (45/100) against fair (35/100) for 1.4006 +QT550.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1.4006 +A and 1.4006 +QT550 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.