Stainless Steel 301 vs 321
Stainless Steel · grade comparison
Stainless Steel 301 and 321 are both stainless steel grades. 301 is the stronger of the two: yield strength 570 MPa (82.7 ksi) against 240 MPa (34.8 ksi) for 321, about 138% more; tensile strength follows at 900 MPa (131 ksi) vs 620 MPa (89.9 ksi). In exchange, 321 is the more ductile: elongation 45% versus 25% for 301, and 301 is harder (270 HB vs 150 HB). 321 runs hotter in service (870°C vs 425°C continuous). On the shop floor, 321 welds better (excellent vs good) and 301 sits in a lower cost tier (premium, $$$) than 321 (high, $$$$).
301Choose it when strength drives the design, or when cost is the deciding factor.
321Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
301 vs 321: 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.
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: Elastic (Young's) Modulus 193 GPa28 Msi · 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)
Latent Heat of Fusion
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.4 % IACS · Electrical Resistivity 7.2×10⁻⁷ Ω·m28.3 µΩ·in
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)
Polishability
Same in both: Brazeability / Solderability 60 / 100
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 Shock Resistance Index
Same in both: Thermal Diffusivity 4.1 mm²/s
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 | 321 |
|---|---|---|
| CNC machining | — | Yes |
| Default condition | Cold Rolled | Solution Annealed |
| Relative cost | $$$ Premium | $$$$ High |
| Min. machined wall | — | 0.8 mm |
| Best machined surface | — | Ra 1.6 µm |
| AlCrN | — | Yes |
| AlTiN | — | Yes |
| CVD Al2O3 | — | Yes |
| CVD TiCN | — | Yes |
| CVD TiN | — | Yes |
| CrN | — | Yes |
| DLC | — | Yes |
| HVOF Coating | — | Yes |
| MoS2 | — | Yes |
| Multilayer CVD | — | Yes |
| TiAlN | — | Yes |
| TiB2 | — | Yes |
| TiCN | — | Yes |
| TiN | — | Yes |
| WC/C | — | Yes |
| ZrN | — | Yes |
Both are offered for Sheet metal. They share 16 finishes: Black Oxide, Cerakote, Chrome Plating, Electroless Nickel (EN), Electropolishing, Epoxy Coating, Gold Plating, Hard Chrome Plating, Nickel Plating, PTFE Coating, Painting, Passivation (Stainless Steel) and 4 more.
301 vs 321 — frequently asked
Is 301 stronger than 321?
Yes. 301 has a typical yield strength of 570 MPa (82.7 ksi) against 240 MPa (34.8 ksi) for 321 — about 138% more. Tensile strength is 900 MPa (131 ksi) vs 620 MPa (89.9 ksi).
Which is cheaper, 301 or 321?
301 is the lower-cost material: it sits in the premium tier ($$$) while 321 is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which welds better, 301 or 321?
321. Its weldability rates excellent (88/100) against good (65/100) for 301.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 301 and 321 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.