Stainless Steel 1.4729-QT vs 1.4729-SR
Stainless Steel · 1.4729 temper comparison
1.4729-QT and 1.4729-SR are two conditions of the same stainless steel grade, 1.4729: QT (quenched and tempered) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. 1.4729-QT is the stronger of the two: yield strength 750 MPa (109 ksi) against 440 MPa (63.8 ksi) for 1.4729-SR, about 70% more; tensile strength follows at 1,000 MPa (145 ksi) vs 700 MPa (102 ksi). In exchange, 1.4729-SR is the more ductile: elongation 8% versus 4% for 1.4729-QT, and 1.4729-QT is harder (355 HB vs 245 HB). 1.4729-SR runs hotter in service (850°C vs 600°C continuous). On the shop floor, 1.4729-SR machines more easily (33 vs 18 out of 100).
1.4729-QTChoose it when strength drives the design.
1.4729-SRChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
1.4729-QT vs 1.4729-SR: 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 215 GPa31.2 Msi · Shear Modulus 83 GPa12 Msi · Bulk Modulus 165 GPa23.9 Msi · Poisson's Ratio 0.29
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 1,470°C2,678 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 24 W/m·K13.9 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 260 J/g112 BTU/lb · Min Service Temperature -20°C-4 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.5 % IACS · Electrical Resistivity 7×10⁻⁷ Ω·m27.6 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.3 V · Corrosion Resistance 45 / 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 65 / 100 · Brazeability / Solderability 40 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 45 MJ/kg19,347 BTU/lb · Embodied Carbon (primary production) 3.4 kg CO₂/kg · Embodied Water 130 L/kg15.6 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.
1.4729-QT vs 1.4729-SR — frequently asked
Is 1.4729-QT stronger than 1.4729-SR?
Yes. 1.4729-QT has a typical yield strength of 750 MPa (109 ksi) against 440 MPa (63.8 ksi) for 1.4729-SR — about 70% more. Tensile strength is 1,000 MPa (145 ksi) vs 700 MPa (102 ksi).
Which condition does FabDigit quote by default, QT or SR?
A is the default 1.4729 condition in the FabDigit quote flow (neither QT nor SR). 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, 1.4729-QT or 1.4729-SR?
1.4729-SR, by a small margin. Both rate poor for machinability — 33/100 against 18/100 for 1.4729-QT.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1.4729-QT and 1.4729-SR 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.