Stainless Steel 1.4938 +QT vs 1.4938 +U
Stainless Steel · 1.4938 temper comparison
1.4938 +QT and 1.4938 +U are two conditions of the same stainless steel grade, 1.4938: +QT (quenched and tempered) versus +U (hot rolled). The chemistry is identical, so every difference below comes from the condition. 1.4938 +QT is the stronger of the two: yield strength 800 MPa (116 ksi) against 750 MPa (109 ksi) for 1.4938 +U, about 7% more. 1.4938 +QT is the more ductile: elongation 17% versus 14% for 1.4938 +U, and 1.4938 +U is harder (320 HB vs 300 HB). 1.4938 +QT runs hotter in service (550°C vs 400°C continuous).
1.4938 +QTChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
1.4938 +QT 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)
Elongation at Break
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
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 %)
Weldability
Formability (cold)
Same in both: 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 +QT vs 1.4938 +U — frequently asked
Is 1.4938 +QT stronger than 1.4938 +U?
Yes. 1.4938 +QT has a typical yield strength of 800 MPa (116 ksi) against 750 MPa (109 ksi) for 1.4938 +U — about 7% more. Tensile strength is 980 MPa (142 ksi) vs 1,050 MPa (152 ksi).
Which condition does FabDigit quote by default, +QT or +U?
+QT is the default 1.4938 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, 1.4938 +QT or 1.4938 +U?
1.4938 +QT. Its machinability rates fair (38/100) against poor (32/100) for 1.4938 +U; for welding the order is 1.4938 +QT first (fair, 35/100) then 1.4938 +U (poor, 30/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1.4938 +QT 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.