1.PDC coal mining tools 2.ore mining, many type 3.good price,high quality 4.professional manufacurer 5 ... of both home and abroad to come for business talks.About products1. Integral drill steels ... lengths.A comprehensive range of button bits, cross bits and chisel bits with (6, 7, 11, ... face, Drop centre, Normal and Retrac body.Tungsten carbide (Buttons): Spherical, Ballistic and Conical. (Threaded R32 ...