... dominant products are chisel bits, cross bits, buttons bits, DTH bits with high, medium and low air pressure, symmetric drilling ... tools, eccentric drilling tools, standardized API system casings, bit shanks and casing tubes which are fit for hydraulic drilling ... ,R32,R38,T38,T45,T51Down-The-Hole Tools1) DTH BIT---65MM to 254mm.2) DTH Hammer---76MM /90MM /110MM 3) Face ShapeConvex--- ...