Oxygen Free Copper Alloy (UNS C10940)

Topics Covered

Chemical Composition
Physical Properties
Other Designations


Copper and its alloys are best suited for applications that require excellent electrical and thermal conductivity. Pure copper is denoted by the UNS numbers C10100 to 13000. The nature and the quantity of the impurities added to copper determines the type of applications that the alloy can be used for.

Copper alloys that are free from oxygen content are best suited for applications that require high ductility and conductivity. Copper C10940 alloy is available in the form of bus bars, rods and shapes. It is used in the form of a brazing filler metal. It exhibits very good corrosion resistance, in the presence of atmospheric corroding agents and brackish or sea water. However, exposure to oxidizing environments or oxidizing acids or moist halogens must be avoided.

This datasheet will elaborate on the chemical composition and properties of copper UNS C10940 alloy.

Chemical Composition

The chemical composition of oxygen copper UNS C10940 is given in the following table.

Element Content (%)
Copper, Cu 99.9
Oxygen 0.02 max
Silver 0.085

Physical Properties

The following table lists the physical properties of copper UNS C10940.

Properties Metric Imperial
Density 8.9 gm/cm3 0.323 lb/in3

Other Designations

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Some of the other designations that are used to denote copper UNS C10940 are as below:-

  • ASTM B187
  • QQ-B-650


Some of the methods adopted for fabricating this alloy are coining, bending, coppersmith, upsetting and drawing. Other methods of fabrication are knurling, roll threading, spinning, swaging and stamping.

Forging - Copper UNS C10940 alloy has good forging ability.

Hot working - Copper UNS C10940 alloy has excellent hot working abilities.

Cold working - Copper UNS C10940 alloy has excellent cold working properties.


Copper UNS C10940 is used in the following applications:

  • Waveguides, lead-in-wires, co-axial cables
  • Bus bars and bus conductors
  • Anodes for vacuum tubes, vacuum seals, transistor components
  • Glass-to-metal seals, klystrons, rectifiers
  • Microwave tubes


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