... IADC:116,517,537,617 4.oil drilling, water well drilling 5.ISO,SGS approve Rock Bit1.Type:TCI -tungsten carbide insert ... .we can make the diamater size of the rock bits as cutomers request.the diamater size show ... execlPls see other details:Available IADC code of rock bits Milled tooth:116,117,126,127,136 ... 637,737.Contact:Rita FengPhone:86-18730702717 water well Rock Bit for hard formation size 8 1/2''