U drill, also known as the quick drill, is a kind of internal cooling drill with good cutting performance, high efficiency, and continuous drilling. The front end of the cutter body is equipped with a replaceable blade, which reduces the cost of use. The difference between a U-drill and a regular drill is that a U-drill uses inserts—a peripheral insert and a center insert. After the tool is worn, it can be replaced directly without regrinding. Using indexable inserts saves material over solid hard drills, and the consistency of the inserts makes it easier to control part dimensions. The rigidity of the U-shaped drill is good, and a high feed rate can be used. The processing diameter of the U-shaped drill is much larger than that of the ordinary drill, and the maximum can reach D50~60mm.