The tool life is closely related to the cutting amount. When making the cutting amount, the reasonable tool life should be selected first, and the reasonable tool life should be determined according to the optimized target.
Generally, the maximum productivity tool life and the lowest cost tool life are two, the former according to the goal of minimum work hours determined, the latter based on the lowest cost of the operation of the target determination. The following points can be considered when selecting tool life depending on the complexity of the tool, the manufacturing and the cost of sharpening. Complex and precision tool life should be chosen more than a single-edged tool. For the machine clamp indexable tool, due to short tool change time, in order to give full play to its cutting performance, improve production efficiency, tool life can be selected lower, generally take 15-30min. For the installation of knives, tool changer and more complex multi-knife machine tools, combined machine tools and automated machining tools, tool life should be selected higher, especially to ensure tool reliability. The productivity of a process in the workshop limits the productivity of the whole workshop, the tool life of the process should be chosen lower when the total cost of the plant is shared in the unit time of an operation, the tool life should also be chosen lower. Large-size finishing, in order to ensure the completion of at least one pass, to avoid cutting in the middle of the knife, tool life should be determined by the accuracy of the parts and surface roughness. Compared with the ordinary machine tool processing method, the CNC machining has put forward the higher request to the tool, not only needs the good, the precision is high, but also requires the dimensional stability, the durability is high, the break and the row performance altar simultaneously requests the installment adjustment convenient, thus satisfies the CNC machine tool High efficiency request. The tools used in CNC machines are often adapted to high-speed cutting tools such as high-speed steel, ultra-fine-grained carbide, and indexable inserts.