Alloy 145 , Tellurium Copper ( C14500 )

Tellurium copper—also referred to as Alloy 145, Alloy C14500, 145 half-hard tellurium, and TeCu—is a copper-based alloy that contains varying amounts of tellurium and phosphorus. The tellurium content typically ranges between 0.4–0.7%, while the phosphorus content ranges between 0.004–0.12%.

Tellurium copper demonstrates good electrical and thermal conductivity, good formability and high machinability. These properties make it suitable for a wide range of industrial applications.


Chemical Composition
(%max., unless shown as range or min.)
  Cu(1)(2) P Te
Min./Max. 99.90 min .004-.012 .40-.7
Nominal 99.50 .008 .55


Properties of Tellurium Copper

Mechanical, chemical, electrical, and characteristic of tellurium copper include:

Resistance to atmospheric corrosion

High thermal (205 BTU/ft2/ft/hr/°F) and electrical conductivity (90% as per IACS)

Resistance to hydrogen embrittlement (i.e., fracturing and weakening caused by the introduction and diffusion of hydrogen)

Tensile strength of 47,900 psi (approximately 38 to 48 ksi)

Yield strength of 44,200 psi (approximately 30 to 40 ksi)

Elongation capabilities ranging between 4–12%

Hardness between 65–130 HV

Structural integrity up to 350° Celsius

Good formability (for cold and hot forming processes)

Machinability rating of 85–90% (where free cutting brass is 100)

Suitability for soldering and brazing

Unsuitability for specific welding processes, such as coated metal arc welding, oxy-acetylene welding, resistance welding, seam welding, or spot welding




  • Material is according to EN 12164 R250 (Half-hard) condition.
  • Please see table below for mechanical properties:




Applications and Industries Served by Tellurium Copper

Due to its unique properties—such as its corrosion resistance, machinability and electrical, and thermal conductivity—tellurium copper finds application in a variety of industries, including:

  • Welding
  • Plumbing
  • Electrical



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