OSNA-Cu58® has been specially developed for cutting purposes. It is a low-alloyed copper material based on technically oxygen-free copper added with tellurium or sulphur. These additions considerably improve the cutting properties of copper without loss of its other typical properties, especially conductivity.

When it comes to machine cutting pure copper shows difficulties. The formation of long pure copper chips slows down the operation when drilling and turning, and results in rapid deterioration of cutting tools. When using CNC-control, and on conventional autolathes, the processing of pure copper is normally not efficient in terms of time, manpower and tooling. Here OSNA-Cu58® is a perfect combination that offers excellent cutting properties and high electrical and thermal conductivity.

OSNA-Cu58® has achieved an excellent record in many areas of industry. It is ideal for the economical manufacture of:

  • bases for diodes and thyristors
  • torch tips in gas welding
  • screws, nuts, contact and fixtures in electrical engineering
  • miniature plug-and-socket connectors and other small parts in electronics
  • screwed pipe connections, cut fittings and similar parts when used instead of machining brass in cases where higher corrosion resistance is required


OSNA-Cu58® has excellent machining properties. In particular the cutting properties of OSNA-Cu58®Te are much closer to those of machining brass than of unalloyed copper as shown in the chart below.

For certain applications finished products made of machining copper have to be galvanically coated with silver, nickel, gold, etc. Various types of copper behave differently in the electrolyte:

OSNA-Cu58® Te: In some electrolytes, such as silvering baths, the deposit turns black.This discoloration can be avoided by galvanic pre-coppering of the part, whereby the copper coating must be free from pores. This can be achieved by using suitable electrolytes (e. g. bright copper bath) at approx. plating thickness of approx. 15μm.

OSNA-Cu58® S: This copper material is also liable to blackening of untreated parts in silver baths. This can also be avoided by galvanic pre-coppering, as with OSNA-Cu58® Te.

Even though its cold-forming properties are inevitably slightly reduced, being especially developed for machining applications, the cold-forming properties of OSNA-Cu58® still compare favourably with other copper alloys.

OSNA-Cu58® materials are suitable for soft and hard soldering. It has better mechanical properties at high temperatures than standard Cu-ETP/C110 copper. This is advantageous for soft-soldering. I
Welding of OSNA-Cu58® is not recommended. The welding seam easily becomes porous or vulnerable to cracks. Therefore welding should be avoided wherever possible.

Tellurium copper scrap should not be mixed with normal unalloyed copper scrap. We are prepared to service you by taking back the copper scrap. For further information please contact us.

OSNA-Cu58® can be drilled dry. However, a thorough coating with light cutting oil, as applied for turning, is indicated in order to minimise cutting tool wear.
For thread cutting, the thread should be manufactured by rolling (hobbing) to avoid disrupting the material’s grain structure. Furthermore, thread rolling improves the fatigue strength.

For turning OSNA-Cu58®, the same carbide tools in CNC-controlled automatic lathes can be used as for machining brass.