... offered Material : 50Mn , 42CrMo Focus on Customers Excavator part slewing ring Kato , Komatsu , Hitachi Excavator part slewing ringCaterpillar : CAT320B CAT320C CATE200B CAT320 SH120A1 ... ,R220-7,R225-7,R290-7,R280,R300,Hitachi :EX60-1,EX60,EX60-5,EX100-1,EX120-1,EX120,EX120-5,EX120-2,EX120-3 ...