Stainless Steel 20Cb-3 vs Alloy 20
Stainless Steel · grade comparison
Stainless Steel 20Cb-3 and Alloy 20 are both stainless steel grades. 20Cb-3 is the stronger of the two: yield strength 345 MPa (50 ksi) against 310 MPa (45 ksi) for Alloy 20, about 11% more. On the shop floor, 20Cb-3 sits in a lower cost tier (premium, $$$) than Alloy 20 (specialty, $$$$$).
20Cb-3Choose it when strength drives the design, or when cost is the deciding factor.
20Cb-3 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.
Bulk Modulus
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
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 · Tensile Strength (Ultimate) 620 MPa89.9 ksi · Reduction in Area 60% · Hardness, Brinell 160 HB
Physical
Density and transition temperatures.
Melting Point (Solidus)
Liquidus Temperature
Same in both: Density 8.08 g/cm³0.29 lb/in³
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Latent Heat of Fusion
Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 14.8 µm/m·K8.2 µin/in·°F · Max Service Temperature (continuous) 500°C932 °F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 1.6 % IACS · Electrical Resistivity 1.08×10⁻⁶ Ω·m42.5 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
Weldability
Formability (cold)
Brazeability / Solderability
Castability
Same in both: Machinability Rating (AISI 1212 = 100 %) 40% · Polishability 75 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Water
Typical Recycled Content
Same in both: Embodied Carbon (primary production) 7.5 kg CO₂/kg
Common Calculations
Ratios derived from the values above.
Modulus of Resilience
Thermal Diffusivity
Same in both: Specific Strength (UTS / density) 77 kN·m/kg · Specific Stiffness (E / density) 23.9 MN·m/kg · 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 | Alloy 20 |
|---|---|---|
| Default condition | Solution Annealed | Annealed |
| Relative cost | $$$ Premium | $$$$$ Specialty |
| Min. machined wall | 0.8 mm | 0.8 mm |
| Best machined surface | Ra 1.6 µm | Ra 1.6 µm |
Both are offered for CNC machining and Sheet metal. Both take the same 32 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, CrN, DLC, Electroless Nickel (EN), Electropolishing and 20 more.
20Cb-3 vs Alloy 20 — frequently asked
Is 20Cb-3 stronger than Alloy 20?
Yes. 20Cb-3 has a typical yield strength of 345 MPa (50 ksi) against 310 MPa (45 ksi) for Alloy 20 — about 11% more. Tensile strength is 620 MPa (89.9 ksi) vs 620 MPa (89.9 ksi).
Which is cheaper, 20Cb-3 or Alloy 20?
20Cb-3 is the lower-cost material: it sits in the premium tier ($$$) 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, 20Cb-3 or Alloy 20?
Alloy 20. Its machinability rates fair (38/100) against poor (33/100) for 20Cb-3; for welding the order is Alloy 20 first (very good, 80/100) then 20Cb-3 (very good, 75/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 20Cb-3 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.