Core barrels are used to cut an annular ring in rock or concrete or reinforced concrete. The center core of the rock or concrete is usually crushed with rock auger. The most important advantage of a core barrel is that it assists to concentrate the torque and crowd force on a small ring of cutting teeth.

Core barrels are generally divided into two types:

1. Core Barrel with Bullet Bits ( Applicable for strong rock up to 100MPa or Rock with deep cracks)
2. Core Barrel with Roller Bits (Applicable for very strong rock formations with compressive strength greater than 100MPa)