| REFERENCE NUMBER DIFFERENTIATING CHARACTERISTICS | ZREQUIRED CHEMICAL CONTENT COPPER PLUS SILVER 99.96 PCT MIN MAX IMPURITIES LIMITATIONS,LEAD 0.0010 PCT,MERCURY 0.0001 PCT,PHOSPHORUS 0.0003 PCT,SULPHUR 0.0040 PCT,ZINC 0.0003 PCT,TOTAL OTHER ELEMENTS 0.0343 PCT 8 IN. DIA,LG,A/A BILLET |