Stainless Steel 1.4008 +A vs 1.4008 QT-HH
Stainless Steel · 1.4008 temper comparison
1.4008 +A and 1.4008 QT-HH are two conditions of the same stainless steel grade, 1.4008: +A (annealed) versus QT-HH (Q&T high hardness). The chemistry is identical, so every difference below comes from the condition. 1.4008 QT-HH is the stronger of the two: yield strength 950 MPa (138 ksi) against 380 MPa (55.1 ksi) for 1.4008 +A, about 150% more; tensile strength follows at 1,150 MPa (167 ksi) vs 590 MPa (85.6 ksi). In exchange, 1.4008 +A is the more ductile: elongation 22% versus 8% for 1.4008 QT-HH, and 1.4008 QT-HH is harder (375 HB vs 180 HB). 1.4008 +A runs hotter in service (600°C vs 350°C continuous). On the shop floor, 1.4008 +A machines more easily (good vs poor) and 1.4008 +A welds better (fair vs poor).
1.4008 +AChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
1.4008 QT-HHChoose it when strength drives the design.
1.4008 +A vs 1.4008 QT-HH: 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)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
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
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.
Max Service Temperature (continuous)
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 · 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
Polishability
Same in both: Formability (cold) 10 / 100 · Castability 65 / 100 · Brazeability / Solderability 45 / 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 QT-HH — frequently asked
Is 1.4008 QT-HH stronger than 1.4008 +A?
Yes. 1.4008 QT-HH has a typical yield strength of 950 MPa (138 ksi) against 380 MPa (55.1 ksi) for 1.4008 +A — about 150% more. Tensile strength is 1,150 MPa (167 ksi) vs 590 MPa (85.6 ksi).
Which condition does FabDigit quote by default, +A or QT-HH?
+QT1 is the default 1.4008 condition in the FabDigit quote flow (neither +A nor QT-HH). 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 QT-HH?
1.4008 +A. Its machinability rates good (55/100) against poor (22/100) for 1.4008 QT-HH; for welding the order is 1.4008 +A first (fair, 45/100) then 1.4008 QT-HH (poor, 25/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1.4008 +A and 1.4008 QT-HH 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.