Cobalt-Chrome Alloy Stellite 12 vs Stellite 6
Cobalt-Chrome Alloy · grade comparison
Cobalt-Chrome Alloy Stellite 12 and Stellite 6 are both cobalt-chrome alloy grades. Stellite 12 is the stronger of the two: yield strength 650 MPa (94.3 ksi) against 541 MPa (78.5 ksi) for Stellite 6, about 20% more. Stellite 12 is harder — 48 HRC against 40 HRC for Stellite 6 — which matters for wear surfaces and threads. On the shop floor, Stellite 6 welds better (good vs fair) and Stellite 12 sits in a lower cost tier (high, $$$$) than Stellite 6 (specialty, $$$$$).
Stellite 12Choose it when strength drives the design, or when surface hardness matters.
Stellite 6Choose it when it will be welded.
Stellite 12 vs Stellite 6: 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.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elongation at Break 1% · Fracture Toughness (K_IC) 25 MPa·√m22.8 ksi·√in · Charpy V-Notch Impact (RT) 5 J3.7 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
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Min Service Temperature
Same in both: Max Service Temperature (continuous) 800°C1,472 °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) -0.25 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Same in both: Machinability 8 / 100 · Machinability Rating (AISI 1212 = 100 %) 5% · Castability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Typical Recycled Content
Same in both: Embodied Energy (primary production) 150 MJ/kg64,488 BTU/lb · Embodied Carbon (primary production) 13 kg CO₂/kg · Embodied Water 400 L/kg47.9 gal/lb
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 4
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 | Stellite 12 | Stellite 6 |
|---|---|---|
| Default condition | — | As Cast |
| Relative cost | $$$$ High | $$$$$ Specialty |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Stellite 12 vs Stellite 6 — frequently asked
Is Stellite 12 stronger than Stellite 6?
Yes. Stellite 12 has a typical yield strength of 650 MPa (94.3 ksi) against 541 MPa (78.5 ksi) for Stellite 6 — about 20% more. Tensile strength is 830 MPa (120 ksi) vs 834 MPa (121 ksi).
Which is cheaper, Stellite 12 or Stellite 6?
Stellite 12 is the lower-cost material: it sits in the high tier ($$$$) while Stellite 6 is specialty ($$$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which welds better, Stellite 12 or Stellite 6?
Stellite 6. Its weldability rates good (55/100) against fair (35/100) for Stellite 12.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Stellite 12 and Stellite 6 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.