1.drill pipe 2.Taper:6,7,11,12. 3.ISO9001 certificate 4. ... ,12 degree taper) taper rods in most lengths.button bits, cross type bits and chisel bits with(6,7,11,12 ... ,38mm,etc.8. Blast furnace tap hole drill tools.(Rod, Cross type bits, button bits and X type bits etc) drill ...