Historical
ISO 6624-1:2001
Internal combustion engines - Piston rings - Part 1: Keystone rings made of cast iron
This part of ISO 6624 specifies the essential dimensional features of keystone rings made of cast iron, types T, TB, TBA, TM, K, KB, KBA and KM, having diameters of from 70 mm up to and including 200 mm, used in reciprocating internal combustion piston engines.
International Organization for Standardization [iso]