This specification covers refined silver in cast bar form in three grades as follows: Grade 99.90 (UNS P07020)-Silver having a minimum fineness of 999.0 commonly referred to as "commercial bar" or "bullion." Grade 99.95 (UNS P07015)-Silver having a minimum fineness of 999.5. Grade 99.99 (UNS P07010)-A premium grade having a minimum fineness of 999.9. The values stated in inch-pound units are to be regarded as the standard.