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Stainless Steel 309Cb 1/2H vs 309Cb 1/4H

Stainless Steel · 309Cb temper comparison

309Cb 1/2H and 309Cb 1/4H are two conditions of the same stainless steel grade, 309Cb: 1/2H (half hard) versus 1/4H (quarter hard). The chemistry is identical, so every difference below comes from the condition. 309Cb 1/2H is the stronger of the two: yield strength 760 MPa (110 ksi) against 515 MPa (74.7 ksi) for 309Cb 1/4H, about 48% more; tensile strength follows at 1,035 MPa (150 ksi) vs 860 MPa (125 ksi). In exchange, 309Cb 1/4H is the more ductile: elongation 20% versus 10% for 309Cb 1/2H, and 309Cb 1/2H is harder (300 HB vs 250 HB).

309Cb 1/2HChoose it when strength drives the design.

309Cb 1/4HChoose it when the part is bent, formed or impact-loaded.

309Cb 1/2H vs 309Cb 1/4H: properties

309Cb 1/2H309Cb 1/4H

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

1,035 MPa150 ksi
860 MPa125 ksi

Yield Strength (0.2% offset)

760 MPa110 ksi
515 MPa74.7 ksi

Elongation at Break

10%
20%

Reduction in Area

30%
40%

Compressive Strength

760 MPa110 ksi
515 MPa74.7 ksi

Shear Strength

620 MPa89.9 ksi
520 MPa75.4 ksi

Fatigue Strength (Endurance Limit)

400 MPa58 ksi
340 MPa49.3 ksi

Fracture Toughness (K_IC)

100 MPa·√m91 ksi·√in
125 MPa·√m114 ksi·√in

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
85 J62.7 ft·lbf

Hardness, Brinell

300 HB
250 HB

Hardness, Rockwell B

85 HRB
100 HRB

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 0.29

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.

Max Service Temperature (continuous)

700°C1,292 °F
750°C1,382 °F

Same in both: Thermal Conductivity 15.6 W/m·K9 BTU/hr·ft·°F · 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.

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

63 / 100
64 / 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

30 / 100
34 / 100

Machinability Rating (AISI 1212 = 100 %)

30%
35%

Weldability

65 / 100
72 / 100

Formability (cold)

20 / 100
32 / 100

Same in both: 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 1/2H vs 309Cb 1/4H — frequently asked

Is 309Cb 1/2H stronger than 309Cb 1/4H?

Yes. 309Cb 1/2H has a typical yield strength of 760 MPa (110 ksi) against 515 MPa (74.7 ksi) for 309Cb 1/4H — about 48% more. Tensile strength is 1,035 MPa (150 ksi) vs 860 MPa (125 ksi).

Which condition does FabDigit quote by default, 1/2H or 1/4H?

Annealed is the default 309Cb condition in the FabDigit quote flow (neither 1/2H nor 1/4H). 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 1/2H or 309Cb 1/4H?

309Cb 1/4H. Its weldability rates very good (72/100) against good (65/100) for 309Cb 1/2H.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 309Cb 1/2H and 309Cb 1/4H 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.