... stable and super quality in suitable price 3. ISO9001:2008 Guilin Diamond Industrial Co., Ltd was established in1961, and is ... diamond bit, composite slice bit,diamond oil bit Diamond double-tube bit and reamerNormal sizeBitReamerScrew threadExternal diameterInternal diameterExternal diameterInternal ... to the full, medium-hard,hard and rigid strata;3)gear and zigzag labial surface suitable to the full ...