The general principle of tool selection: easy installation and adjustment, good reliability, good rigidity, durability and high precision. Under the premise of meeting the processing requirements, try to choose a tool with a shorter tool holder to enhance the rigidity of the machining.

1) Select the tool according to the surface size of the workpiece
When selecting a tool, the size of the tool should be adapted to the surface size of the workpiece. In production, the contours around the plane parts are often machined with end mills; for milling planes, carbide inserts should be selected. When machining the bosses and grooves, select the high-speed steel end mill; when machining the surface of the blank or roughing the hole, you can use the corn milling cutter with the carbide insert; for the processing of some three-dimensional and variable bevel contours, select The disc milling cutter, the round nose knife and the flat knife are used for rough machining, and the ball end milling cutter, the ring milling cutter and the conical milling cutter are used for finishing.

2) Select the tool according to the surface shape of the workpiece
In the mold processing, since the cutting speed of the end of the ball-end tool is zero, in order to ensure the machining accuracy, the cutting distance is generally the tip-tight distance, so the ball-end milling cutter is often used for the finishing of the curved surface. The flat-blade tool is superior to the ball-end knives in terms of surface quality and cutting efficiency. Therefore, the flat-blade knives should be preferred if the surface is roughed or finished under the premise of ensuring no cutting. In addition, the durability and accuracy of the tool are highly dependent on the tool price. It must be noted that in most cases, the choice of a good tool increases the tool cost, but the resulting processing quality and processing efficiency increase. , can make the entire processing cost greatly reduced.

3) Reasonably arrange the order of the tools
In the machining process of economical CNC machine tools, since the wear, measurement and replacement of the tools are mostly manual and manual, the occupation time is long. Therefore, the arrangement order of the tools must be arranged reasonably. Generally, the following principles should be followed:

1, the process is concentrated once, the same tool can complete all the processing steps;
2, rough finishing tools should be used separately;
3, first face back hole;
4 ,first surface finishing, then 2D contour finishing;
5, Rational use of automatic tool change function of CNC machine tools to improve production efficiency;
6 ,Minimize the number of tools.