1. First of all, the difference between U drill and ordinary drill is that U drill uses the peripheral blade and center blade of the blade. From this point of view, the relationship between U drill and ordinary hard drill is actually similar to that of machine clamp turning tool and welding turning tool. , The blade can be replaced directly without re-grinding after the tool is worn. After all, the use of indexable inserts saves material than solid drills, and the consistency of the inserts makes it easier to control the size of the parts.

2. The U drill has better rigidity and can use a high feed rate, and the processing diameter of the U drill is much larger than that of the ordinary drill, and the maximum can reach D50~60mm. Of course, the U drill is impossible to do due to the characteristics of the insert. Is too small.

3. U drills only need to replace the same type and different grades of blades when encountering various materials. Hard drills are not so convenient.