什麽是基准面和基准线钳工同志在工件上画线时,总要先选择一个表面或一根基线,来作为根据,然后再画其他表面的位置和尺寸。机工同志在机床上加工工件时,也总要先选择一个表面,作为定位和加工的根据。这些用来作为施工根据的面或线,就是这里所要谈的基准面和基准线,—般把它们笼统地叫 When it comes to drawing lines on workpieces, always choose a surface or a baseline as the basis and then draw the positions and dimensions of the other surfaces. When a mechanic works a workpiece on a machine tool, a surface must always be selected as the basis for positioning and machining. These are the faces or lines used as a basis for construction, which are the datums and datums to be talked about here. They are generally called