... and many quality system certificates.KAISHAN is the only manufacturer in china which is able to mass produce the motor powered and diesel powered ... .>R-screw drill ,screw connecting sleeve. ( R28,R32,R38 The diameter is form 38 to 102mm)2.>T-screw drill ,screw connecting ... sleeve. (T38,T45,T51 The diameyer is form 76 to127mm)III. Down the hole impact drill .1.Down the hole rock drill with low ...