Cobalt-Chrome Alloy AWS BCo-1 vs Stellite 21
Cobalt-Chrome Alloy · grade comparison
Cobalt-Chrome Alloy AWS BCo-1 and Stellite 21 are both cobalt-chrome alloy grades. AWS BCo-1 is harder — 52 HRC against 32 HRC for Stellite 21 — which matters for wear surfaces and threads. AWS BCo-1 runs hotter in service (980°C vs 760°C continuous) and Stellite 21 conducts heat better (14.8 W/m·K vs 13 W/m·K). On the shop floor, Stellite 21 machines more easily (poor vs not recommended), Stellite 21 welds better (good vs not recommended), and Stellite 21 forms better (poor vs not recommended).
AWS BCo-1Choose it when surface hardness matters, or when the part sees heat.
Stellite 21Choose it when the part is machined in volume, or when it will be welded.
AWS BCo-1 vs Stellite 21: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all cobalt-chrome alloy 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 cobalt-chrome alloy 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.
Shear Strength
Hardness, Rockwell C
Hardness, Vickers
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
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
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Min Service Temperature
Latent Heat of Fusion
Electrical
Conductivity and insulation.
Electrical Resistivity
Electrical Conductivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Galvanic Potential (seawater, vs SCE)
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Brazeability / Solderability
Machinability Rating (AISI 1212 = 100 %)
Castability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Typical Recycled Content
Embodied Water
Common Calculations
Ratios derived from the values above.
Thermal Diffusivity
Strength versus weight
Yield strength against density for every cobalt-chrome alloy grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | AWS BCo-1 | Stellite 21 |
|---|---|---|
| Default condition | — | As Cast |
| Relative cost | $$$$ High | $$$$$ Specialty |
| Min. machined wall | — | — |
| Best machined surface | — | — |
AWS BCo-1 vs Stellite 21 — frequently asked
What is the difference between AWS BCo-1 and Stellite 21?
Cobalt-Chrome Alloy AWS BCo-1 and Stellite 21 are both cobalt-chrome alloy grades. AWS BCo-1 is harder — 52 HRC against 32 HRC for Stellite 21 — which matters for wear surfaces and threads. AWS BCo-1 runs hotter in service (980°C vs 760°C continuous) and Stellite 21 conducts heat better (14.8 W/m·K vs 13 W/m·K).
Which is cheaper, AWS BCo-1 or Stellite 21?
AWS BCo-1 is the lower-cost material: it sits in the high tier ($$$$) while Stellite 21 is specialty ($$$$$). 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, AWS BCo-1 or Stellite 21?
Stellite 21. Its machinability rates poor (15/100) against not recommended (5/100) for AWS BCo-1; for welding the order is Stellite 21 first (good, 55/100) then AWS BCo-1 (not recommended, 10/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in AWS BCo-1 and Stellite 21 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.