Stainless Steel 1.4008 +A vs 1.4008 +QT1
Stainless Steel · 1.4008 temper comparison
1.4008 +A and 1.4008 +QT1 are two conditions of the same stainless steel grade, 1.4008: +A (annealed) versus +QT1 (quenched (≈ 950–1050 °C) and high-tempered (≈ 650–700 °C), Rp0.2 ≥ 440…). The chemistry is identical, so every difference below comes from the condition. 1.4008 +QT1 is the stronger of the two: yield strength 500 MPa (72.5 ksi) against 380 MPa (55.1 ksi) for 1.4008 +A, about 32% more; tensile strength follows at 690 MPa (100 ksi) vs 590 MPa (85.6 ksi). In exchange, 1.4008 +A is the more ductile: elongation 22% versus 18% for 1.4008 +QT1, and 1.4008 +QT1 is harder (210 HB vs 180 HB). On the shop floor, 1.4008 +A machines more easily (good vs fair).
1.4008 +AChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
1.4008 +QT1Choose it when strength drives the design.
1.4008 +A vs 1.4008 +QT1: 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
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 78 GPa11.3 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 500 MPa72.5 ksi · Shear Strength 420 MPa60.9 ksi · Fracture Toughness (K_IC) 85 MPa·√m77.4 ksi·√in · Hardness, Rockwell C 18 HRC · Hardness, Vickers 220 HV
Physical
Density and transition temperatures.
Same in both: Density 7.7 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,400°C2,552 °F · Liquidus Temperature 1,500°C2,732 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 25 W/m·K14.4 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 · Max Service Temperature (continuous) 600°C1,112 °F · 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).
Same in both: Galvanic Potential (seawater, vs SCE) -0.3 V · Corrosion Resistance 45 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Same in both: Formability (cold) 10 / 100 · Castability 65 / 100 · Brazeability / Solderability 45 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 53 MJ/kg22,786 BTU/lb · Embodied Carbon (primary production) 3.6 kg CO₂/kg · Embodied Water 200 L/kg24 gal/lb · Typical Recycled Content 70%
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.
1.4008 +A vs 1.4008 +QT1 — frequently asked
Is 1.4008 +QT1 stronger than 1.4008 +A?
Yes. 1.4008 +QT1 has a typical yield strength of 500 MPa (72.5 ksi) against 380 MPa (55.1 ksi) for 1.4008 +A — about 32% more. Tensile strength is 690 MPa (100 ksi) vs 590 MPa (85.6 ksi).
Which condition does FabDigit quote by default, +A or +QT1?
+QT1 is the default 1.4008 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, 1.4008 +A or 1.4008 +QT1?
1.4008 +A. Its machinability rates good (55/100) against fair (42/100) for 1.4008 +QT1; for welding the order is 1.4008 +A first (fair, 45/100) then 1.4008 +QT1 (fair, 40/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1.4008 +A and 1.4008 +QT1 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.