nc reduces the amount of non-chip-producing time by selecting speeds and feeds, making rapid moves between surfaces to be cut, using automatic fixtures, automatic tool changing, controlling the coolant, in-process gauging, and loading and unloading the part nc(产品简称)通过选择速率,高速转变切割面,自动改变工具,控制冷却剂,减少了这些不必要的非工作时间,工作中划定规格,和装卸降低了这些不必要的非制造时间。