Stainless Steel 1.4938 +QT1100 vs 1.4938 +U
Stainless Steel · 1.4938 temper comparison
1.4938 +QT1100 and 1.4938 +U are two conditions of the same stainless steel grade, 1.4938: +QT1100 (quenched and tempered at lower temperature, 1000–1200 MPa) versus +U (hot rolled). The chemistry is identical, so every difference below comes from the condition. 1.4938 +QT1100 is the stronger of the two: yield strength 930 MPa (135 ksi) against 750 MPa (109 ksi) for 1.4938 +U, about 24% more. 1.4938 +QT1100 is harder — 340 HB against 320 HB for 1.4938 +U — which matters for wear surfaces and threads. 1.4938 +QT1100 runs hotter in service (500°C vs 400°C continuous).
1.4938 +QT1100Choose it when strength drives the design, or when surface hardness matters.
1.4938 +QT1100 vs 1.4938 +U: 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)
Reduction in Area
Compressive Strength
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 216 GPa31.3 Msi · Shear Modulus 83 GPa12 Msi · Bulk Modulus 166 GPa24.1 Msi · Poisson's Ratio 0.3 · Elongation at Break 14%
Physical
Density and transition temperatures.
Same in both: Density 7.75 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °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) 10.5 µm/m·K5.8 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 %)
Formability (cold)
Same in both: Weldability 30 / 100 · Castability 40 / 100 · Brazeability / Solderability 40 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 55 MJ/kg23,646 BTU/lb · Embodied Carbon (primary production) 4.3 kg CO₂/kg · Embodied Water 190 L/kg22.8 gal/lb · Typical Recycled Content 55%
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.
1.4938 +QT1100 vs 1.4938 +U — frequently asked
Is 1.4938 +QT1100 stronger than 1.4938 +U?
Yes. 1.4938 +QT1100 has a typical yield strength of 930 MPa (135 ksi) against 750 MPa (109 ksi) for 1.4938 +U — about 24% more. Tensile strength is 1,100 MPa (160 ksi) vs 1,050 MPa (152 ksi).
Which condition does FabDigit quote by default, +QT1100 or +U?
+QT is the default 1.4938 condition in the FabDigit quote flow (neither +QT1100 nor +U). 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.
When should I choose 1.4938 +QT1100 over 1.4938 +U?
Pick 1.4938 +QT1100 when strength drives the design, or when surface hardness matters.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1.4938 +QT1100 and 1.4938 +U 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.