Stainless Steel 1.4418 +A vs 1.4418 +QT840
Stainless Steel · 1.4418 temper comparison
1.4418 +A and 1.4418 +QT840 are two conditions of the same stainless steel grade, 1.4418: +A (annealed) versus +QT840 (quenched and tempered, Rm 840–980 MPa). The chemistry is identical, so every difference below comes from the condition. 1.4418 +QT840 is the stronger of the two: yield strength 700 MPa (102 ksi) against 600 MPa (87 ksi) for 1.4418 +A, about 17% more; tensile strength follows at 900 MPa (131 ksi) vs 800 MPa (116 ksi). In exchange, 1.4418 +A is the more ductile: elongation 20% versus 18% for 1.4418 +QT840, and 1.4418 +QT840 is harder (275 HB vs 260 HB). 1.4418 +A runs hotter in service (350°C vs 320°C continuous).
1.4418 +AChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
1.4418 +QT840Choose it when strength drives the design.
1.4418 +A vs 1.4418 +QT840: 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 C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 166 GPa24.1 Msi · Poisson's Ratio 0.3 · Compressive Strength 790 MPa115 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 1,480°C2,696 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 15 W/m·K8.7 BTU/hr·ft·°F · Specific Heat Capacity 430 J/kg·K0.1 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 -60°C-76 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.2 % IACS · Electrical Resistivity 8×10⁻⁷ Ω·m31.5 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.3 V · Corrosion Resistance 55 / 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: Castability 60 / 100 · Brazeability / Solderability 40 / 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) 5.5 kg CO₂/kg · Embodied Water 200 L/kg24 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.
1.4418 +A vs 1.4418 +QT840 — frequently asked
Is 1.4418 +QT840 stronger than 1.4418 +A?
Yes. 1.4418 +QT840 has a typical yield strength of 700 MPa (102 ksi) against 600 MPa (87 ksi) for 1.4418 +A — about 17% more. Tensile strength is 900 MPa (131 ksi) vs 800 MPa (116 ksi).
Which condition does FabDigit quote by default, +A or +QT840?
+QT900 is the default 1.4418 condition in the FabDigit quote flow (neither +A nor +QT840). 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, 1.4418 +A or 1.4418 +QT840?
1.4418 +A, by a small margin. Both rate fair for machinability — 42/100 against 37/100 for 1.4418 +QT840.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1.4418 +A and 1.4418 +QT840 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.