The standard to which you are referring, ASTM B 62 Standard Specification for Composition Bronze or Ounce Metal Castings has most recently been revised in 2002. This revision has no mention of Grade 1. Only one composition is given, with requirements for mechanical properties, etc. The grade is commonly referred to as 85-5-5-5, which means 85Cu, 5Sn, 5Pb, and 5Zn. The UNS designation is C83600.