1.Diamond bits 2.coal mining,many types 3.good ... (Tapered Drill Steel)Including:Drill rods with Shank H22x108mm,(6,7,11,12 degree taper) taper rods in most ... bits, cross type bits and chisel bits with(6,7,11,12 degree taper).Bit diameter:28mm-57mm ... U118 And coal bolting bit and coal bolting rod.6. All kinds of casing bits for shield machine and ... bits, button bits and X type bits etc) Diamond bits