... as well, and our dominant products are chisel bits, cross bits, buttons bits, DTH bits with high, medium and low air pressure, symmetric ... reliability of the products.Tapered Drill BitType --Chisel Bits / Cross Bits / Button Bits Diameter---28mm,30mm 32mm,34mm,36mm,40mm,42mm,44mmThread ... to 254mm.2) DTH Hammer---76MM /90MM /110MM 3) Face ShapeConvex---Suitable for soft rock ( less than 1033.5bar)Concave ...