... center type. 2.Premium quality nickel-alloy steel 5"high air pressure dth bits 1)Design in the form of ... Mach, Digger etc. Parameter DRILL BITBIT,DIA.(mm)NO.AIR HOLESGAUGE BUTTONSFRONT BUTTONSWEIGHT(kg) DHD13028X16 4X14,3X14 15.0 13328X16 ... 4X14,3X14 150 1402 8X16 4X1,4 4X14 16.0 1462 8X16 4X14,4X14 18.0 ... 0 QL501302 8X16 7X14 14.5 1332 8X16 7X14 14.5 1402 7X18 7X14 15.5 1462 8X16 8X14 15.6 ...