Stainless Steel 254 SMO vs Alloy 20
Stainless Steel · grade comparison
Stainless Steel 254 SMO and Alloy 20 are both stainless steel grades, both corrosion resistant ss. 254 SMO is the stronger of the two: yield strength 350 MPa (50.8 ksi) against 310 MPa (45 ksi) for Alloy 20, about 13% more; tensile strength follows at 700 MPa (102 ksi) vs 620 MPa (89.9 ksi). 254 SMO is the more ductile: elongation 45% versus 40% for Alloy 20, and 254 SMO is harder (190 HB vs 160 HB). Alloy 20 runs hotter in service (500°C vs 400°C continuous) and 254 SMO conducts heat better (14 W/m·K vs 12 W/m·K). On the shop floor, Alloy 20 machines more easily (fair vs poor) and 254 SMO sits in a lower cost tier (premium, $$$) than Alloy 20 (specialty, $$$$$).
254 SMOChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
Alloy 20Choose it when the part sees heat, or when the part is machined in volume.
254 SMO vs Alloy 20: 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
Shear Modulus
Bulk Modulus
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: Poisson's Ratio 0.3
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).
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)
Castability
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 45%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Same in both: Thermal Shock Resistance Index 3
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 | 254 SMO | Alloy 20 |
|---|---|---|
| Default condition | Solution Annealed | Annealed |
| Relative cost | $$$ Premium | $$$$$ Specialty |
| Min. machined wall | 0.8 mm | 0.8 mm |
| Best machined surface | Ra 1.6 µm | Ra 1.6 µm |
Both are offered for CNC machining and Sheet metal. Both take the same 32 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, CrN, DLC, Electroless Nickel (EN), Electropolishing and 20 more.
254 SMO vs Alloy 20 — frequently asked
Is 254 SMO stronger than Alloy 20?
Yes. 254 SMO has a typical yield strength of 350 MPa (50.8 ksi) against 310 MPa (45 ksi) for Alloy 20 — about 13% more. Tensile strength is 700 MPa (102 ksi) vs 620 MPa (89.9 ksi).
Which is cheaper, 254 SMO or Alloy 20?
254 SMO is the lower-cost material: it sits in the premium tier ($$$) while Alloy 20 is specialty ($$$$$). 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, 254 SMO or Alloy 20?
Alloy 20. Its machinability rates fair (38/100) against poor (25/100) for 254 SMO; for welding the order is Alloy 20 first (very good, 80/100) then 254 SMO (very good, 75/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 254 SMO and Alloy 20 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.