... clay,quarrying,mining,construction button bit 2.button,thread,tapered bit 3.chisel,cross,button etc Oil ... chisel bit and taper cross bit), thread bit( R thread and T thread), retrac bit and dth bit( from ... 3" to 8" are available)I. Thread button bits specifications:1) Bit body : normal type ... . Single-chisel type rock drill bits : For light drill machine cut high hardness is not drill layers, ...