Stainless Steel ER309-AW vs ER309 PWHT
Stainless Steel · ER309 temper comparison
ER309-AW and ER309 PWHT are two conditions of the same stainless steel grade, ER309: AW (as-welded deposit) versus PWHT (post-weld heat treated). The chemistry is identical, so every difference below comes from the condition. ER309-AW is the stronger of the two: yield strength 400 MPa (58 ksi) against 300 MPa (43.5 ksi) for ER309 PWHT, about 33% more; tensile strength follows at 600 MPa (87 ksi) vs 550 MPa (79.8 ksi). In exchange, ER309 PWHT is the more ductile: elongation 45% versus 38% for ER309-AW, and ER309-AW is harder (180 HB vs 160 HB).
ER309-AWChoose it when strength drives the design.
ER309 PWHTChoose it when the part is bent, formed or impact-loaded.
ER309-AW vs ER309 PWHT: 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 196 GPa28.4 Msi · Shear Modulus 76 GPa11 Msi · Bulk Modulus 145 GPa21 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.
Same in both: Thermal Conductivity 15 W/m·K8.7 BTU/hr·ft·°F · Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 15.5 µm/m·K8.6 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 1,000°C1,832 °F · Min Service Temperature -100°C-148 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.2 % IACS · Electrical Resistivity 7.8×10⁻⁷ Ω·m30.7 µΩ·in
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 · Brazeability / Solderability 55 / 100 · Polishability 65 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 62 MJ/kg26,655 BTU/lb · Embodied Carbon (primary production) 5.2 kg CO₂/kg · Embodied Water 130 L/kg15.6 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.
ER309-AW vs ER309 PWHT — frequently asked
Is ER309-AW stronger than ER309 PWHT?
Yes. ER309-AW has a typical yield strength of 400 MPa (58 ksi) against 300 MPa (43.5 ksi) for ER309 PWHT — about 33% more. Tensile strength is 600 MPa (87 ksi) vs 550 MPa (79.8 ksi).
Which condition does FabDigit quote by default, AW or PWHT?
AW is the default ER309 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 ER309-AW over ER309 PWHT?
Pick ER309-AW when strength drives the design. Pick ER309 PWHT when the part is bent, formed or impact-loaded.
Ready to make it?
Upload a CAD file and FabDigit prices the part in ER309-AW and ER309 PWHT 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.