Reasonable choice of cutting parameters principle is roughing, mainly to increase productivity in general, but also should consider the economic and processing costs; semi-finishing and finishing, should be the premise of ensuring the quality of processing, taking into account the cutting efficiency, economy and processing costs. Specific values should be based on the machine instructions, cutting the amount of manual and combined on experience.

⑴ cutting depth t. In the machine tool, workpiece and tool rigidity permitting, t is equal to the allowance, which is an effective measure to improve productivity. To ensure accuracy and surface roughness of parts, generally should be left a margin for finishing. CNC machine finishing allowance may be slightly smaller than the ordinary machine tools.

⑵ cutting width l. L generally proportional to the tool diameter d, and is inversely proportional to the depth of cut. Economical CNC machining, generally ranges from l: l = (0.6 ~ 0.9) d.

⑶ cutting speed v. V is also a measure to improve the productivity increase, but the relationship between v and tool life more closely. With the increase of v, the tool life sharp decline, so the choice depends on v tool life. In addition, the cutting and processing of materials have a great relationship, for example, when using the vertical milling cutter alloy steel 30crni2mova, v can be 8m / min or so; but with the same end mill for milling aluminum alloys, v optional 200m / min or more .