¡ôAs for harder bedrock, large flood rubble and hard perpetually frozen soil, it is very difficult to use spiral bit or rotary drilling bit directly. Trunk annular bit shall be used in combination with spiral bit and sand bit.
¡ôHose bits consist of core annular trunk bit and non-core annular trunk bit, and the diameter of bit is between 400 mm and 3000 mm.
¡ôWe could produce Core Barrel with Roller-Bit in various outer diameters and different pitches subject to customers' demand.