... Bit1.Type:TCI -tungsten carbide insert and Milled tooth2.Available size: 85.5MM,88.9MM,98.4MM,114.3MM,117.5MM ... .1MM,381.0MM,444.5MM.we can make the diamater size of the rock bits as cutomers request.the diamater ... size show in execlPls see other details:Available IADC code of ... FengPhone:86-18730702717 water well Rock Bit for hard formation size 8 1/2''