... Zhongrui can manufacturer the best qualith DTH drill bit, DTH water well drilling hammer . Now we can supply 90mm-254mm(3. ... 360,380, COP44, COP54, COP64, COP84 , 3"-8" DTH water well drilling hammer, 340,350,360,380 4",5",6",8 ... " quick water well drilling hammer with very good price and service. No.ModelOutside ... 7Mpa)15-34API(4 1/2)" REG195-254 360 water well drilling hammer