Cobalt-Chrome Alloy F75 vs Ultimet
Cobalt-Chrome Alloy · grade comparison
Cobalt-Chrome Alloy F75 and Ultimet are both cobalt-chrome alloy grades. Ultimet is the stronger of the two: tensile strength 1,000 MPa (145 ksi) against 720 MPa (104 ksi) for F75, about 39% more. Ultimet is the more ductile: elongation 39% versus 10% for F75, and F75 is harder (300 HB vs 277 HB). Ultimet runs hotter in service (900°C vs 600°C continuous) and F75 conducts heat better (14 W/m·K vs 11 W/m·K). On the shop floor, Ultimet welds better (very good vs poor) and F75 sits in a lower cost tier (premium, $$$) than Ultimet (high, $$$$).
F75Choose it when cost is the deciding factor.
UltimetChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
F75 vs Ultimet: 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
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Poisson's Ratio 0.3
Physical
Density and transition temperatures.
Density
Liquidus Temperature
Same in both: Melting Point (Solidus) 1,330°C2,426 °F
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)
Same in both: Latent Heat of Fusion 270 J/g116 BTU/lb · 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)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Castability
Brazeability / Solderability
Polishability
Same in both: Machinability Rating (AISI 1212 = 100 %) 10%
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 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 | F75 | Ultimet |
|---|---|---|
| CNC machining | Yes | — |
| 3D printing | Yes | — |
| Default condition | As Cast | — |
| Relative cost | $$$ Premium | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
| Electropolishing | Yes | — |
| Passivation (Stainless Steel) | Yes | — |
F75 vs Ultimet — frequently asked
Is Ultimet stronger than F75?
Yes. Ultimet has a typical tensile strength of 1,000 MPa (145 ksi) against 720 MPa (104 ksi) for F75 — about 39% more.
Which is cheaper, F75 or Ultimet?
F75 is the lower-cost material: it sits in the premium tier ($$$) while Ultimet 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, F75 or Ultimet?
Ultimet. Its machinability rates poor (18/100) against not recommended (12/100) for F75; for welding the order is Ultimet first (very good, 75/100) then F75 (poor, 25/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in F75 and Ultimet 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.