Tapered chisel bits and cross bits (taper 7, 12degree), mostly use for hand rock drill. we make them by alloy steel by forging and select suitable tungsten carbide insert by customers’ requests according to their stone types. such as for limestone, marble, granite etc. \n\nspecification: chisel bits: 20mm-45mm; cross bits: 32mm-50mm; button bits: 32mm-50mm tapered drill rod: h22x108mm, h19x108mm shank. length 400mm-4800mm.