Stainless Steel 20Cb-3 vs Alloy 803
Stainless Steel · grade comparison
Stainless Steel 20Cb-3 and Alloy 803 are both stainless steel grades. 20Cb-3 is the stronger of the two: yield strength 345 MPa (50 ksi) against 265 MPa (38.4 ksi) for Alloy 803, about 30% more; tensile strength follows at 620 MPa (89.9 ksi) vs 585 MPa (84.8 ksi). Alloy 803 runs hotter in service (1,100°C vs 500°C continuous). On the shop floor, 20Cb-3 welds better (very good vs good), 20Cb-3 forms better (very good vs good), and 20Cb-3 sits in a lower cost tier (premium, $$$) than Alloy 803 (high, $$$$).
20Cb-3Choose it when strength drives the design, or when it will be welded.
Alloy 803Choose it when the part sees heat.
20Cb-3 vs Alloy 803: 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
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 193 GPa28 Msi · Shear Modulus 74 GPa10.7 Msi · Poisson's Ratio 0.3 · Shear Strength 400 MPa58 ksi
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
Specific Heat Capacity
Max Service Temperature (continuous)
Latent Heat of Fusion
Same in both: Thermal Expansion (CTE, 20–100 °C) 14.8 µm/m·K8.2 µin/in·°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)
Same in both: Corrosion Resistance 72 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Polishability
Castability
Same in both: Brazeability / Solderability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 40%
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 | 20Cb-3 | Alloy 803 |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| Default condition | Solution Annealed | — |
| Relative cost | $$$ Premium | $$$$ High |
| Min. machined wall | 0.8 mm | — |
| Best machined surface | Ra 1.6 µm | — |
| AlCrN | Yes | — |
| AlTiN | Yes | — |
| Black Oxide | Yes | — |
| CVD Al2O3 | Yes | — |
| CVD TiCN | Yes | — |
| CVD TiN | Yes | — |
| Cerakote | Yes | — |
| Chrome Plating | Yes | — |
| CrN | Yes | — |
| DLC | Yes | — |
| Electropolishing | Yes | — |
| HVOF Coating | Yes | — |
| MoS2 | Yes | — |
| Multilayer CVD | Yes | — |
| Nickel Plating | Yes | — |
| PTFE Coating | Yes | — |
| Painting | Yes | — |
| Passivation (Stainless Steel) | Yes | — |
They share 7 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Pickling, Plasma Spray, Silver Plating.
20Cb-3 vs Alloy 803 — frequently asked
Is 20Cb-3 stronger than Alloy 803?
Yes. 20Cb-3 has a typical yield strength of 345 MPa (50 ksi) against 265 MPa (38.4 ksi) for Alloy 803 — about 30% more. Tensile strength is 620 MPa (89.9 ksi) vs 585 MPa (84.8 ksi).
Which is cheaper, 20Cb-3 or Alloy 803?
20Cb-3 is the lower-cost material: it sits in the premium tier ($$$) while Alloy 803 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, 20Cb-3 or Alloy 803?
20Cb-3, by a small margin. Both rate poor for machinability — 33/100 against 27/100 for Alloy 803; for welding the order is 20Cb-3 first (very good, 75/100) then Alloy 803 (good, 65/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 20Cb-3 and Alloy 803 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.