机械工厂的切削加工有两种，分别称为“粗切削”和“精切削”。

There are two kinds of cuts in machine- shop work called, respectively, the "roughing cut" and the "finishing cut".

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有些加工，如精度要求不高或需要切除的金属量较小，也可能只需一次精切削。

Also, in some jobs, fot example, when great accuracy is not needed, or when a comparatively small amount of metal must be removed, a finishing cut may be all that is required.

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一般地说，钢质棒料、锻件、铸件等只经一次粗切削和一次精切削即可达到所要求的形状和尺寸。

Generally speaking, bars of steel, forging, castings, etc. are machined to the required shape and size with only one roughing and one finishing cut.

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