... Trustworth With yeas of experience, now Zhongrui can manufacturer the best qualith DTH rock drill bit, DTH hammer. ... Now we can supply 90mm-254mm(3.5"-10") DTH rock drill bit, 340,350, ... 360,380, COP44, COP54, COP64, COP84 , 3"-8" DTH hammer, 340,350,360,380 4",5",6 ... bitOuter dia. of pilot bitMatch hammerWeight(kg)183mm163mm188mm140mm160mmZRC130G60.3 The most popular rock drill bit