Nickel Alloy Kovar-CD vs Kovar-O
Nickel Alloy · Kovar temper comparison
Kovar-CD and Kovar-O are two conditions of the same nickel alloy grade, Kovar: CD (cold drawn) versus O (annealed). The chemistry is identical, so every difference below comes from the condition. Kovar-CD is the stronger of the two: yield strength 540 MPa (78.3 ksi) against 345 MPa (50 ksi) for Kovar-O, about 57% more; tensile strength follows at 660 MPa (95.7 ksi) vs 520 MPa (75.4 ksi). In exchange, Kovar-O is the more ductile: elongation 30% versus 14% for Kovar-CD, and Kovar-CD is harder (209 HB vs 145 HB). Kovar-O runs hotter in service (450°C vs 300°C continuous).
Kovar-CDChoose it when strength drives the design.
Kovar-OChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
Kovar-CD vs Kovar-O: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all nickel 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 nickel 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.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 138 GPa20 Msi · Shear Modulus 52 GPa7.5 Msi · Bulk Modulus 126 GPa18.3 Msi · Poisson's Ratio 0.32
Physical
Density and transition temperatures.
Same in both: Density 8.36 g/cm³0.3 lb/in³ · Melting Point (Solidus) 1,450°C2,642 °F · Liquidus Temperature 1,455°C2,651 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 17 W/m·K9.8 BTU/hr·ft·°F · Specific Heat Capacity 439 J/kg·K0.1 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 5.5 µm/m·K3.1 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).
Same in both: Galvanic Potential (seawater, vs SCE) -0.45 V · Corrosion Resistance 28 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Brazeability / Solderability 90 / 100 · Polishability 65 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 100 MJ/kg42,992 BTU/lb · Embodied Carbon (primary production) 8 kg CO₂/kg · Typical Recycled Content 25%
Strength versus weight
Yield strength against density for every nickel alloy grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Kovar-CD vs Kovar-O — frequently asked
Is Kovar-CD stronger than Kovar-O?
Yes. Kovar-CD has a typical yield strength of 540 MPa (78.3 ksi) against 345 MPa (50 ksi) for Kovar-O — about 57% more. Tensile strength is 660 MPa (95.7 ksi) vs 520 MPa (75.4 ksi).
Which condition does FabDigit quote by default, CD or O?
O is the default Kovar condition in the FabDigit quote flow. The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.
Which is easier to machine, Kovar-CD or Kovar-O?
Kovar-CD. Its machinability rates fair (38/100) against poor (32/100) for Kovar-O; for welding the order is Kovar-O first (very good, 80/100) then Kovar-CD (very good, 75/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in Kovar-CD and Kovar-O 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.