size:77/8(200mm) IADC:845 Tooth type:tungsten carbide insert connection :41/2" API Reg bearing:rubber sealed roller bearing Nozzle:three jet nozzles application:waterwell,oilwell,HDD,exploration,etc weight:37kg certificate:API7-1,SY/T5164,ISO9001:2008 Recommend rock formation: hard formation with high abrasiveness, such as hard limestone, dolomite, hard sandstone and chert, etc
