ISO/TR 12245:1994 PDF

The system is used to classify rubber grade carbon blacks by the use of a four-character nomenclature system. The first character gives some indication of the influence of the carbon black on the rate of cure of a typical rubber compound containing the black, the second character gives information on the average particle size of the carbon black, and the last two characters are assigned arbitrarily. All rubber grade carbon blacks for which a number is currently assigned at the time of publication of this classification system are listed in two tables. Assignment of a number is exclusively the ASTM D-24 Committee's responsibility.