Stainless Steel 309S-1/4 Hard vs 309S Cold Drawn
Stainless Steel · 309S temper comparison
309S-1/4 Hard and 309S Cold Drawn are two conditions of the same stainless steel grade, 309S: 1/4 Hard (quarter hard) versus Cold Drawn. The chemistry is identical, so every difference below comes from the condition. 309S-1/4 Hard is the stronger of the two: yield strength 520 MPa (75.4 ksi) against 480 MPa (69.6 ksi) for 309S Cold Drawn, about 8% more; tensile strength follows at 760 MPa (110 ksi) vs 700 MPa (102 ksi). In exchange, 309S Cold Drawn is the more ductile: elongation 25% versus 20% for 309S-1/4 Hard, and 309S-1/4 Hard is harder (240 HB vs 220 HB). On the shop floor, 309S Cold Drawn machines more easily (fair vs poor).
309S-1/4 HardChoose it when strength drives the design.
309S Cold DrawnChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
309S-1/4 Hard vs 309S Cold Drawn: 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 0.3
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.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 15.5 W/m·K9 BTU/hr·ft·°F · Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 15 µm/m·K8.3 µin/in·°F · Latent Heat of Fusion 270 J/g116 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
Same in both: Galvanic Potential (seawater, vs SCE) -0.05 V
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: Brazeability / Solderability 65 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 62 MJ/kg26,655 BTU/lb · Embodied Carbon (primary production) 4.6 kg CO₂/kg · Embodied Water 300 L/kg35.9 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.
309S-1/4 Hard vs 309S Cold Drawn — frequently asked
Is 309S-1/4 Hard stronger than 309S Cold Drawn?
Yes. 309S-1/4 Hard has a typical yield strength of 520 MPa (75.4 ksi) against 480 MPa (69.6 ksi) for 309S Cold Drawn — about 8% more. Tensile strength is 760 MPa (110 ksi) vs 700 MPa (102 ksi).
Which condition does FabDigit quote by default, 1/4 Hard or Cold Drawn?
Solution Annealed is the default 309S condition in the FabDigit quote flow (neither 1/4 Hard nor Cold Drawn). 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, 309S-1/4 Hard or 309S Cold Drawn?
309S Cold Drawn. Its machinability rates fair (45/100) against poor (32/100) for 309S-1/4 Hard; for welding the order is 309S Cold Drawn first (very good, 80/100) then 309S-1/4 Hard (very good, 75/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 309S-1/4 Hard and 309S Cold Drawn 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.