Commonly used drills for precision parts processing include center drills, standard twist drills, reamer drills, deep hole drills and counter hole drills. Center drill: Mainly used for hole positioning. Due to the small diameter of the cut part, a higher speed should be selected when center drills are used to drill holes. Standard twist drill: The cutting part of the twist drill includes two main cutting edges, two auxiliary cutting edges, one chisel edge and two spiral flutes. Since there is no fixing device for guiding the drilling mold, the drilling on the machining center will be affected by the asymmetry of the cutting force on the two cutting edges, which can easily cause the drilling deflection. Therefore, the two cutting edges of the drill must have high grinding accuracy when machining precision parts (the two blades have the same length, and the apex angle is symmetrical to the center line of the drill, or drill the center first, and then use the drill to drill) Standard reamer: Standard reamer usually has 3 to 4 main cutting edges. The material of the cutting parts is high-speed steel or cemented carbide. The structure includes straight shank, taper shank and sleeve type. In small batch production, twist drills are often converted to standard reamer drills. Deep hole drilling: When processing deep holes, poor heat dissipation, difficulty in chip removal, and poor rigidity of the drill rod can easily damage the parts and cause the axis of the hole to deviate, which affects the processing accuracy and productivity. Therefore, deep hole drilling is selected. Countersinking: countersinking is mainly used for processing tapered countersinks or flat-bottomed countersinks. The main problem of countersinking is the occurrence of vibration marks on the end face or taper surface of the countersink. Therefore, special attention should be paid to the correct selection of tool parameters and cutting parameters during the countersinking process. It is very important to select suitable drills for correct processing when processing precision parts, otherwise it will cause damage to the parts. To ensure the quality of processing, you must regularly check the life of the drill bit if you need to change it, in order to achieve high-efficiency processing quality.