With the development of numerical control technology , quickly developed a milling tool , milling cutter can control the size and shape of each layer precision milling , on the other hand also to the next level allowance milling reduce cumulative burden. Precision tooling , the higher the degree of approximation of string space curve , the more space micro- line segment , the longer the program . The actual processing, roughing can choose the low point accuracy to reduce the number of sections of the program . Milling tool according to the characteristics and requirements of applications , the advantages of integrated materials, coatings and groove , and be "right " type of development , so that the blade within a certain range of applications with a performance advantage , get a good processing effect , generally allows processing efficiency above 20%. Milling cutter durability and precision tool prices great relationship with . Attention is necessary in most cases , a good choice of the tool while the tool increases the cost , but the resulting processing quality and efficiency, the overall cost can be lower than using normal tools, resulting in better benefits.