... 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 ... -hard rock (1033.5bar~2067bar)Plate ---Suitable for had rock ( more than 2067bar)Drill RodSteel Drill Rod---H19/H22, Length: 0.5M to ...