... :Phosphated, Nitrided etc. 3.ISO9002,QS9000,TS16949 Piston Ringpiston ring for Komatsu 6D105 engine:1.piston ring material :nodular iron, cast iron, steel ... , OM314, OM352, OM441, OM442, OM360, OM412, OM401, D2840, OM422, OM355, OM346, OM443Caterpillar piston ringS6KT, 3116(7E5213), CAT110, 3204, 3208, D-330, D ...