38mm 7degree 7buttons Tapered Diamond Core Impact Drill Bit Product Description38mm tapered button bit1.Product Name:tungsten carbide taper button drill bits.TypesTapered chisel bits, Tapered cross bits, Tapered button bits2.Application:Tapered drill bits are used in granite and marble quarry, gold mine, railway, tunnel, etc. for drilling3.Feature:Tapered drill bits connect tapered drill steel of rock drill for drilling holes4.Material:High quality carbide and high quality steel5.MOQ:No requirement for testing and trial order <img src="//wm.cdn.cn86.cn/taianjiuzhou/202...