... Nitrided etc. 3.ISO9002,QS9000,TS16949 Piston Ringpiston ring for Isuzu 4JB1:1.piston ring material :nodular iron, cast iron, steel, alloy ... aslo do as per customer's request)2.piston ring surface treatment:polishing, plating, oxidation, phosphating, etc(we can aslo do ... piston ringS6KT, 3116(7E5213), CAT110, 3204, 3208, D-330, D-336, D-333, D-334, 3304(2W6091),3306(9S3068)3307(2W1709), 3300, 3406 ...