... .clay,quarrying,mining,construction button bit 2.button,thread,tapered bit 3.chisel,cross,button etc Oil ... taper 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 ... to customer's requirement of the Bit Diameter,No.air holes,carbide button shape and the face ...