... granite, quartz, ironstone, chert, abrasive rock etc. Including impregnated diamond core bit, surface-set diamond bit, reaming shells, casing bit, casing ... shoe bit, corelifter, corelifter case, core barrel assembly, inner tube head assembly, over shot, hoist plugs ... , and it is used to couple the drill bit with the core barrel. Its main function is to ream the hole ...