The cutting part of the flat drill is shovel shaped, with a simple structure and low manufacturing cost. The cutting fluid is easily introduced into the hole, but the cutting and chip removal performance is poor. There are two types of structures for flat drills: integral and assembled. The integral type is mainly used for drilling micro holes with a diameter of 0.03-0.5 millimeters. The assembled flat drill blade is interchangeable and can be cooled internally, mainly used for drilling large holes with a diameter of 25-500 millimeters.