Drum core drill

At present, there are two common: tube cutter drill (for medium hard rock and gravel), core drill bits tube (for hard rock and large boulders). In barrel coring drill bit in two categories, and with and without coring device to take points of core devices, depending on the difficulty of coring. Because cone core drill is mainly used for hard rock drilling and drill the ring area, if the conditions can also pass on part in the installation of reverse circulation core drill bit to improve drilling efficiency. 4, belled pile diameter drill bit does not increase without increasing deep foundation piles, in order to improve the bearing capacity of single pile, the design department is often achieved through the pedestal pile, rotary drilling rig construction is expanding bottom without any changes can be construction just choose belled drill can be. Belled drill used to mechanically based, such drills are relatively simple to use and maintain, there is the open and under the open, the opening of the four-link mechanism is generally used for soil, strong winds, weathered even hard rock formations. Due to non-circulation drilling Rotary core drills bits, completion of expansion after the end of the barrel with slag slag can be.