Stainless Steel 1.4125 +QT vs 1.4125-QT500
Stainless Steel · 1.4125 temper comparison
1.4125 +QT and 1.4125-QT500 are two conditions of the same stainless steel grade, 1.4125: +QT (quenched and tempered) versus QT500 (hardened, tempered 450–550 °C). The chemistry is identical, so every difference below comes from the condition. 1.4125 +QT is the stronger of the two: yield strength 1,900 MPa (276 ksi) against 1,650 MPa (239 ksi) for 1.4125-QT500, about 15% more; tensile strength follows at 1,970 MPa (286 ksi) vs 1,800 MPa (261 ksi). In exchange, 1.4125-QT500 is the more ductile: elongation 3% versus 2% for 1.4125 +QT, and 1.4125 +QT is harder (580 HB vs 540 HB). 1.4125-QT500 runs hotter in service (420°C vs 300°C continuous). On the shop floor, 1.4125 +QT welds better (poor vs not recommended).
1.4125 +QTChoose it when strength drives the design, or when it will be welded.
1.4125-QT500Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
1.4125 +QT vs 1.4125-QT500: 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.
Elastic (Young's) Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
Same in both: Shear Modulus 78 GPa11.3 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.28 · Hardness, Rockwell B 99 HRB
Physical
Density and transition temperatures.
Same in both: Density 7.7 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,370°C2,498 °F · Liquidus Temperature 1,480°C2,696 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.2 µm/m·K5.7 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -50°C-58 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
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)
Polishability
Same in both: Castability 35 / 100 · Brazeability / Solderability 45 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 55 MJ/kg23,646 BTU/lb · Embodied Carbon (primary production) 5.2 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.
1.4125 +QT vs 1.4125-QT500 — frequently asked
Is 1.4125 +QT stronger than 1.4125-QT500?
Yes. 1.4125 +QT has a typical yield strength of 1,900 MPa (276 ksi) against 1,650 MPa (239 ksi) for 1.4125-QT500 — about 15% more. Tensile strength is 1,970 MPa (286 ksi) vs 1,800 MPa (261 ksi).
Which condition does FabDigit quote by default, +QT or QT500?
+A is the default 1.4125 condition in the FabDigit quote flow (neither +QT nor QT500). 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, 1.4125 +QT or 1.4125-QT500?
1.4125 +QT. Its weldability rates poor (15/100) against not recommended (5/100) for 1.4125-QT500.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1.4125 +QT and 1.4125-QT500 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.