Tellurium Copper (C145 Copper)

With 40 years of experience supplying nonferrous metals for the metal fabrication market, Sequoia Brass & Copper offers sheets, plates, bars, and more of high-quality materials to a diverse client base. Tellurium copper is just one of the many copper-based alloys we offer in our extensive product catalog at SBC.

Also known as C145 copper, Copper 145, Alloy 145, Alloy C14500, 145 half-hard tellurium, or TeCu, this material contains between 0.4 and 0.7% of tellurium as well as 0.004 and 0.120% of phosphorous. 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.

Properties of Tellurium Copper (C145 Copper)

Falling under the free-machining copper classification, C145 far exceeds the machinability of pure copper. The pure variety has a 20% machinability rating, whereas this alloy’s rating is 85% and allows for increased machining speed and a longer lifecycle for tooling. This is the result of the precipitations of copper telluride within C145’s microstructure generating short chips. Tellurium copper is also a highly conductive material, lending it to applications in the electrical industry.

Some of the mechanical, chemical, electrical, and manufacturing properties characteristic of tellurium copper include:

Resistance to atmospheric corrosion
Resistance to hydrogen embrittlement (i.e., fracturing and weakening caused by the introduction and diffusion of hydrogen)
High thermal (205 BTU/ft.2/ft./hr./° F) and electrical conductivity (90% as per IACS)
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 and 12%
Hardness between 65 and 130 HV
Structural integrity up to 350° C
Good formability (for cold and hot forming processes)
Machinability rating of 85 to 90% (where free-cutting brass is 100%)
Suitability for soldering and brazing
Unsuitability for specific welding processes, such as coated metal arc welding, oxyacetylene welding, resistance welding, seam welding, and spot welding

At Sequoia Brass & Copper, we typically offer tellurium copper in flat bar, round bar forms, or precision saw cut. However, the raw material is also available in hollow rod, hexagonal rod, tube, and wire forms.

Applications & Industries Served by Tellurium Copper (C145 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

Its advantageous properties also make it uniquely suited to use in a variety of high-performance product applications, such as:

Clamps
Contacts
EDM anodes
Electrical connectors
Electrical switches
Fasteners
Motor and switch parts
Pins
Relay parts
Soldering coppers
Sprinkler heads
Welding tips

Tellurium Copper vs. Copper

Pure copper is soft, whereas tellurium copper delivers a hard alternative with high tensile strength. As discussed, the tellurium content within C145 copper causes clean, short chips. This enables manufacturers to cut the material five times as fast as cutting pure copper. In addition to improving machinability and speed, this also reduces tool wear so tooling will last longer. Added to tellurium copper’s high electrical conductivity and hydrogen embrittlement resistance, these factors all make the alloy an optimal material for applications in the electrical industry. As for similarities, C145 copper’s ductility as well as its electrical and thermal conductivity are only marginally different than those same properties in pure copper.

Sequoia Brass & Copper’s Tellurium Copper (C145 Copper) Products

With all its beneficial qualities, C145 copper is ideal for manufacturing high-performance industrial components for markets like plumbing, electrical, and welding. That’s why, as an industry leader in copper supply, SBC has included C145 copper rods and bars as part of our extensive catalog of quality material options.

Our tellurium copper rods are available with outer diameters (ODs) of 0.25 to 3 inches and lengths of 6 to 72 inches. As for our rectangular alloy 145 copper bars, they come in a standard width of 6 inches, with lengths of 12 to 72 inches and thicknesses of 0.25 to 1.25 inches. To best meet your project’s requirements, our team also provides precision saw-cutting on our C145 copper materials.