Stainless Steel 301 vs 309S
Stainless Steel · grade comparison
Stainless Steel 301 and 309S are both stainless steel grades. 301 is the stronger of the two: yield strength 570 MPa (82.7 ksi) against 280 MPa (40.6 ksi) for 309S, about 104% more; tensile strength follows at 900 MPa (131 ksi) vs 550 MPa (79.8 ksi). In exchange, 309S is the more ductile: elongation 45% versus 25% for 301, and 301 is harder (270 HB vs 165 HB). 309S runs hotter in service (1,000°C vs 425°C continuous). On the shop floor, 309S welds better (very good vs good).
301Choose it when strength drives the design.
309SChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
301 vs 309S: 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.
Elastic (Young's) Modulus
Bulk Modulus
Poisson's Ratio
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, Rockwell C
Hardness, Vickers
Same in both: Shear Modulus 77 GPa11.2 Msi
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | 301 | 309S |
|---|---|---|
| CNC machining | — | Yes |
| Default condition | Cold Rolled | Solution Annealed |
| Relative cost | $$$ Premium | $$$ Premium |
| Min. machined wall | — | 0.8 mm |
| Best machined surface | — | Ra 1.6 µm |
| AlCrN | — | Yes |
| AlTiN | — | Yes |
| CVD Al2O3 | — | Yes |
| CVD TiCN | — | Yes |
| CVD TiN | — | Yes |
| CrN | — | Yes |
| DLC | — | Yes |
| HVOF Coating | — | Yes |
| MoS2 | — | Yes |
| Multilayer CVD | — | Yes |
| TiAlN | — | Yes |
| TiB2 | — | Yes |
| TiCN | — | Yes |
| TiN | — | Yes |
| WC/C | — | Yes |
| ZrN | — | Yes |
Both are offered for Sheet metal. They share 16 finishes: Black Oxide, Cerakote, Chrome Plating, Electroless Nickel (EN), Electropolishing, Epoxy Coating, Gold Plating, Hard Chrome Plating, Nickel Plating, PTFE Coating, Painting, Passivation (Stainless Steel) and 4 more.
301 vs 309S — frequently asked
Is 301 stronger than 309S?
Yes. 301 has a typical yield strength of 570 MPa (82.7 ksi) against 280 MPa (40.6 ksi) for 309S — about 104% more. Tensile strength is 900 MPa (131 ksi) vs 550 MPa (79.8 ksi).
Which is cheaper, 301 or 309S?
Both sit in the same relative cost tier ($$$, premium); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which welds better, 301 or 309S?
309S. Its weldability rates very good (80/100) against good (65/100) for 301.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 301 and 309S 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.