Stainless Steel ER309LSi-AW vs ER309LSi-SR
Stainless Steel · ER309LSi temper comparison
ER309LSi-AW and ER309LSi-SR are two conditions of the same stainless steel grade, ER309LSi: AW (as-welded deposit) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. ER309LSi-AW is the stronger of the two: yield strength 400 MPa (58 ksi) against 360 MPa (52.2 ksi) for ER309LSi-SR, about 11% more; tensile strength follows at 590 MPa (85.6 ksi) vs 560 MPa (81.2 ksi). ER309LSi-AW is harder — 185 HB against 175 HB for ER309LSi-SR — which matters for wear surfaces and threads.
ER309LSi-AWChoose it when strength drives the design, or when surface hardness matters.
ER309LSi-AW vs ER309LSi-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 B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.28
Physical
Density and transition temperatures.
Same in both: Density 7.9 g/cm³0.29 lb/in³ · Melting Point (Solidus) 1,400°C2,552 °F · Liquidus Temperature 1,450°C2,642 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 16 µm/m·K8.9 µin/in·°F · Latent Heat of Fusion 285 J/g123 BTU/lb · Max Service Temperature (continuous) 950°C1,742 °F · Min Service Temperature -100°C-148 °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) -0.1 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 92 / 100 · Castability 60 / 100 · Brazeability / Solderability 60 / 100 · Polishability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 60 MJ/kg25,795 BTU/lb · Embodied Carbon (primary production) 5.5 kg CO₂/kg · Embodied Water 200 L/kg24 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.
ER309LSi-AW vs ER309LSi-SR — frequently asked
Is ER309LSi-AW stronger than ER309LSi-SR?
Yes. ER309LSi-AW has a typical yield strength of 400 MPa (58 ksi) against 360 MPa (52.2 ksi) for ER309LSi-SR — about 11% more. Tensile strength is 590 MPa (85.6 ksi) vs 560 MPa (81.2 ksi).
Which condition does FabDigit quote by default, AW or SR?
AW is the default ER309LSi 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.
When should I choose ER309LSi-AW over ER309LSi-SR?
Pick ER309LSi-AW when strength drives the design, or when surface hardness matters.
Ready to make it?
Upload a CAD file and FabDigit prices the part in ER309LSi-AW and ER309LSi-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.