SCIENCE AND TECHNOLOGY ENGLIAH FOR MECHANICAL ENGINEERING Among the various parameters of machining accuracy, the shape accuracy of part surfaces relies on the cutting tools, and the relative motions between cutting tools and workpieces The dimensional accuracy, including accuracy of dimensions of part surfaces themselves and dimensions between part surfaces, can be achieved through different method Methods for Obtaining required Dimensional Accuracy In machining, different measures can be adopted to attain the required dimensional accuracy. There are basically two different methods: trial cutting (or grinding) and automatic dimension maintenance Trial Cutting 试切法 Trial cutting achieves the required dimensional accuracy in several trial cutting(or grinding) passes. A certain length of the surface to be machined is first cut and measured. (c)SCIENCE AND TECHNOLOGY ENGLISH FOR MECHANICAL ENGINEERING Among the various parameters of machining accuracy, the shape accuracy of part surfaces relies on the cutting tools, and the relative motions between cutting tools and workpieces. The dimensional accuracy, including accuracy of dimensions of part surfaces themselves and dimensions between part surfaces, can be achieved through different method. Methods for Obtaining Required Dimensional Accuracy In machining, different measures can be adopted to attain the required dimensional accuracy. There are basically two different methods: trial cutting (or grinding) and automatic dimension maintenance. Trial Cutting Trial cutting achieves the required dimensional accuracy in several trial cutting (or grinding) passes. A certain length of the surface to be machined is first cut and measured.(c) 试切法