Core Barrels and Overshots factory Product Description The core barrel assembly lifts the drill core from the drill rod without picking up the drill bit. All tools include the main parts of drilling tools, overshots, drill pipes, jaws, round wrenches, etc. Their advantages are high suitable for drilling cores from deep layers.Core Barrels and Overshots factory website:http://www.china-zjtk.com/core....-barrels-and-oversho