Atlas Copco engineers combined advanced hard-rock cutting structures with reliable sealed bearing technology to create a complete line of pilot bits and hole openers for the horizontal-directional-drilling market. A full range of sizes and cutting structures are available, ranging in diameter from 4¾ to 17½ inches. Also, Atlas Copco offers random rock split bit hole openers in diameters ranging up from 8 inches. These hole openers utilize custom-designed and manufactured "Random Cutting Structure" bit thirds. Atlas Copco Secoroc initiated the supply of a finished split bit reamer to the HDD industry.