View Sample Alloy Digest Data Sheet (PDF)Since 1952, Alloy Digest has been the leading reference for materials property data on metals and alloys used throughout the world. Featuring graphs, charts and tables, these sheets give facts and figures on composition or characterization, physical and mechanical properties, heat treatment, and machinability.AMTEL is a free-machining copper combining high electrical and thermal conductivities with a machinability rating of 85% of free-cutting brass. (Conventional oxygen-bearing and oxygen-free coppers have ratings of 20%). AMTEL copper offers uniform machinability; in addition, it is resistant to hydrogen embrittlement because it is based on oxygen-free copper.