Stainless Steel 20Cb-3 vs 254 SMO
Stainless Steel · grade comparison
Stainless Steel 20Cb-3 and 254 SMO are both stainless steel grades. 254 SMO is the stronger of the two: tensile strength 700 MPa (102 ksi) against 620 MPa (89.9 ksi) for 20Cb-3, about 13% more. 254 SMO is harder — 190 HB against 160 HB for 20Cb-3 — which matters for wear surfaces and threads. 20Cb-3 runs hotter in service (500°C vs 400°C continuous) and 254 SMO conducts heat better (14 W/m·K vs 12.6 W/m·K). On the shop floor, 20Cb-3 forms better (very good vs good).
20Cb-3Choose it when the part sees heat.
254 SMOChoose it when strength drives the design, or when surface hardness matters.
20Cb-3 vs 254 SMO: 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
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Compressive Strength
Fracture Toughness (K_IC)
Same in both: Poisson's Ratio 0.3 · Charpy V-Notch Impact (RT) 200 J148 ft·lbf
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)
Latent Heat of Fusion
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 %)
Formability (cold)
Polishability
Castability
Same in both: Weldability 75 / 100 · Brazeability / Solderability 55 / 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 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 | 20Cb-3 | 254 SMO |
|---|---|---|
| Default condition | Solution Annealed | Solution Annealed |
| Relative cost | $$$ Premium | $$$ Premium |
| 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.
20Cb-3 vs 254 SMO — frequently asked
Is 254 SMO stronger than 20Cb-3?
Yes. 254 SMO has a typical tensile strength of 700 MPa (102 ksi) against 620 MPa (89.9 ksi) for 20Cb-3 — about 13% more.
Which is cheaper, 20Cb-3 or 254 SMO?
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 is easier to machine, 20Cb-3 or 254 SMO?
20Cb-3, by a small margin. Both rate poor for machinability — 33/100 against 25/100 for 254 SMO.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 20Cb-3 and 254 SMO 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.