Copper Cu 99.97% Min. Silica Si 0.3ppm Max. Cobalt Co 0.2ppm Max. Bismuth Bi 0.1ppm Max. Lead Pb 0.2ppm Max. Tellurium Te 0.05ppm Max. Iron Fe 2ppm Max. Silver Ag 10ppm Max. Aluminum Al 0.5ppm Max. Selenium Se 0.3ppm Max. Manganese Mn 0.1ppm Max. Sulphur S 4ppm Max. Nickel Ni 0.2ppm Max. Magnesium MG 0.4ppm Max. Antimony Sb 0.1ppm Max. Oxygen O 2 0 Arsenic AS 0.1ppm Max.