Precision roller chains must be designated by the standard number indicated in tables 1, 1M, 2 and 2M. The first two digits represent the pitch in sixteenths of an inch. The string numbers in tables 1 and 1M will be followed by the suffix 1, after a hyphen, for single strings, 2 for double strings, 3 for triple strings, etc. For example: 16B-1, 16B-2, 16B-3, etc.