146mm Double Head Casing Drilling Bit Zhuzhou Rockking Engineering Machinery Co., Ltd. Base Info Model NO.：146Surface Treatment：Spray-PaintManufacturing Process：ForgingMaterial：Alloy SteelTrademark：ZZROCKKINGTransport Package：Wooden BoxesOrigin：China Description Pre：R28, R32, R35, R38, T38, T45, Thread Button Drill Bit Next：168mm Double Head Casing Drilling Bit
