Stainless Steel 301 vs S21640
Stainless Steel · grade comparison
Stainless Steel 301 and S21640 are both stainless steel grades. 301 is the stronger of the two: yield strength 570 MPa (82.7 ksi) against 450 MPa (65.3 ksi) for S21640, about 27% more; tensile strength follows at 900 MPa (131 ksi) vs 725 MPa (105 ksi). In exchange, S21640 is the more ductile: elongation 45% versus 25% for 301, and 301 is harder (270 HB vs 200 HB). S21640 runs hotter in service (815°C vs 425°C continuous) and 301 conducts electricity better (2.4 % IACS vs 2 % IACS). On the shop floor, 301 machines more easily (fair vs poor) and 301 sits in a lower cost tier (premium, $$$) than S21640 (high, $$$$).
301Choose it when strength drives the design, or when the part is machined in volume.
S21640Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
301 vs S21640: 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)
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.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
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
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Castability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Water
Typical Recycled Content
Same in both: Embodied Carbon (primary production) 5.8 kg CO₂/kg
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 | S21640 |
|---|---|---|
| Sheet metal | Yes | — |
| Default condition | Cold Rolled | — |
| Relative cost | $$$ Premium | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
| Black Oxide | Yes | — |
| Cerakote | Yes | — |
| Chrome Plating | Yes | — |
| Electropolishing | Yes | — |
| Nickel Plating | Yes | — |
| PTFE Coating | Yes | — |
| Painting | Yes | — |
| Passivation (Stainless Steel) | Yes | — |
| Powder Coating | Yes | — |
They share 7 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Pickling, Plasma Spray, Silver Plating.
301 vs S21640 — frequently asked
Is 301 stronger than S21640?
Yes. 301 has a typical yield strength of 570 MPa (82.7 ksi) against 450 MPa (65.3 ksi) for S21640 — about 27% more. Tensile strength is 900 MPa (131 ksi) vs 725 MPa (105 ksi).
Which is cheaper, 301 or S21640?
301 is the lower-cost material: it sits in the premium tier ($$$) while S21640 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 is easier to machine, 301 or S21640?
301. Its machinability rates fair (35/100) against poor (25/100) for S21640; for welding the order is S21640 first (very good, 70/100) then 301 (good, 65/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 301 and S21640 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.