Double Head Casing Drilling Bit System Zhuzhou Rockking Engineering Machinery Co., Ltd. Base Info Model NO.：118-216mmSurface Treatment：Spray-PaintManufacturing Process：ForgingMaterial：Alloy SteelTrademark：ZZROCKKINGTransport Package：Wooden BoxesOrigin：China Description Pre：DHD350, Cop54, Ql50/5, XL5, M50, SD5 High Air Pressure DTH Drill Bits Next：118 Double Head Casing Drilling Bit System
