Precision machining precision machining technology is introduced in the process on the basis of production to change the object shape, size, relative location and nature to make it become products or semi-finished products, general precision processing to solve the problem of two, including the processing precision, tolerance and dimensional accuracy and surface condition; processing efficiency, some processing can achieve good machining precision, but it is difficult to obtain high machining efficiency. At present, precision machining technology mainly includes fine and fine boring, fine milling and fine grinding, grinding and polishing. The following is a specific introduction.

精车和精镗工艺：飞行器大多数精密的轻合金（铝或镁合金等）零件多采用这种方法加工。一般用天然单晶金刚石刀具,刀刃圆弧半径小于0.1微米。在高精度车床上加工可获得1微米的精度，平均高度差小于0.2微米的表面不平度,坐标精度可达±2微米。

Fine car and fine boring process: most of the precision light alloy (aluminum or magnesium alloy) parts of the aircraft are processed by this method. In general, a natural single crystal diamond tool is used, and the radius of the arc is less than 0.1 microns. The precision of a high precision lathe is 1 microns. The average height difference is less than 0.2 microns, and the precision of the coordinate can be up to 2 microns.

精铣工艺：用于加工形状复杂的铝或铍合金结构件。依靠机床的导轨和主轴的精度来获得较高的相互位置精度。使用经仔细研磨的金刚石刀头进行高速铣切可获得精确的镜面。

Milling process: for the processing of complex shape of aluminum or beryllium alloy structural parts. High precision of mutual position is obtained by the precision of the guide rail and the spindle of the machine tool. Accurate mirror surface can be obtained by high speed milling with a carefully grinded diamond cutter head.

精磨工艺：用于加工轴或孔类零件。这类零件多数采用淬硬钢，有很高的硬度。大多数高精度磨床主轴采用静压或动压液体轴承，以保证高稳定度。磨削的极限精度除受机床主轴和床身刚度的影响外，还与砂轮的选择和平衡、工件中心孔的加工精度等因素有关。精磨可获得 1微米的尺寸精度和0.5微米的不圆度。

Fine grinding process: used for processing shaft or hole parts. This kind of parts used for the majority of hardened steel with high hardness. Most high precision grinder spindle adopts hydrostatic or dynamic pressure liquid bearing to ensure high stability. The ultimate accuracy of grinding is not only affected by the spindle and stiffness of machine bed, but also with the selection and balance of grinding wheel, the machining accuracy of workpiece center hole and so on. Fine grinding can obtain 1 micron dimensional precision and 0.5 micron inroundness.