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Stainless Steel 309Cb 1/4H vs 309Cb-AW

Stainless Steel · 309Cb temper comparison

309Cb 1/4H and 309Cb-AW are two conditions of the same stainless steel grade, 309Cb: 1/4H (quarter hard) versus AW (as-welded deposit). The chemistry is identical, so every difference below comes from the condition. 309Cb 1/4H is the stronger of the two: yield strength 515 MPa (74.7 ksi) against 400 MPa (58 ksi) for 309Cb-AW, about 29% more; tensile strength follows at 860 MPa (125 ksi) vs 590 MPa (85.6 ksi). In exchange, 309Cb-AW is the more ductile: elongation 32% versus 20% for 309Cb 1/4H, and 309Cb 1/4H is harder (250 HB vs 180 HB). 309Cb-AW runs hotter in service (900°C vs 750°C continuous).

309Cb 1/4HChoose it when strength drives the design.

309Cb-AWChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

309Cb 1/4H vs 309Cb-AW: properties

309Cb 1/4H309Cb-AW

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
198 GPa28.7 Msi

Tensile Strength (Ultimate)

860 MPa125 ksi
590 MPa85.6 ksi

Yield Strength (0.2% offset)

515 MPa74.7 ksi
400 MPa58 ksi

Elongation at Break

20%
32%

Compressive Strength

515 MPa74.7 ksi
400 MPa58 ksi

Shear Strength

520 MPa75.4 ksi
380 MPa55.1 ksi

Fatigue Strength (Endurance Limit)

340 MPa49.3 ksi
210 MPa30.5 ksi

Fracture Toughness (K_IC)

125 MPa·√m114 ksi·√in
130 MPa·√m118 ksi·√in

Charpy V-Notch Impact (RT)

85 J62.7 ft·lbf
60 J44.3 ft·lbf

Hardness, Brinell

250 HB
180 HB

Hardness, Rockwell B

100 HRB
88 HRB

Same in both: Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 40%

Physical

Density and transition temperatures.

Same in both: Density 7.98 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

15.6 W/m·K9 BTU/hr·ft·°F
15.2 W/m·K8.8 BTU/hr·ft·°F

Max Service Temperature (continuous)

750°C1,382 °F
900°C1,652 °F

Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 14.9 µm/m·K8.3 µin/in·°F · Latent Heat of Fusion 285 J/g123 BTU/lb · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

7.8×10⁻⁷ Ω·m30.7 µΩ·in
7.9×10⁻⁷ Ω·m31.1 µΩ·in

Same in both: Electrical Conductivity 2.2 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

64 / 100
63 / 100

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 Rating (AISI 1212 = 100 %)

35%
36%

Weldability

72 / 100
80 / 100

Formability (cold)

32 / 100
40 / 100

Same in both: Machinability 34 / 100 · Brazeability / Solderability 60 / 100 · Polishability 65 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 60 MJ/kg25,795 BTU/lb · Embodied Carbon (primary production) 4.8 kg CO₂/kg · Embodied Water 200 L/kg24 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.

3005007001,0001,5002,0007.27.47.67.888.2Density (g/cm³)Yield strength (MPa) — log scale309Cb

309Cb 1/4H vs 309Cb-AW — frequently asked

Is 309Cb 1/4H stronger than 309Cb-AW?

Yes. 309Cb 1/4H has a typical yield strength of 515 MPa (74.7 ksi) against 400 MPa (58 ksi) for 309Cb-AW — about 29% more. Tensile strength is 860 MPa (125 ksi) vs 590 MPa (85.6 ksi).

Which condition does FabDigit quote by default, 1/4H or AW?

Annealed is the default 309Cb condition in the FabDigit quote flow (neither 1/4H nor AW). 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 welds better, 309Cb 1/4H or 309Cb-AW?

309Cb-AW. Its weldability rates very good (80/100) against very good (72/100) for 309Cb 1/4H.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 309Cb 1/4H and 309Cb-AW 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.