cast iron grinding plate

Lapping finish is a precision machining process, in which a thin layer will be removed from the working surface of the cast iron plate by using grinding tools and abrasives. According to the process method, lapping method can be divided into wet lapping, dry lapping and semi-dry lapping. Dry lapping, also know as embedded emery lapping, is the common used finishing method for cast iron surface plate.

 三板互研法：所谓三板互研法是指三块平板互相之间依次互研，并且每块平板只能当下板两遍，实际共研磨6遍。使用这种方法压砂的好处是，三块研磨平板的平面度都很好，三块研磨平板的压砂效果基本一样，并且三块研磨平板都可以使用，不用经常压砂，缺点是加工时间长且每次加工必须制作三块相同的铸铁平板才能完成整个加工，也就是说制作一块研磨平板的成本和制作三块研磨平板的成本是一样的。

Three-piece Lapping Technique:

This type of lapping, involves three lapping plates, in which the three plates are supposed to lapping mutually in proper order and each plate to be lapped at the bottom position just for two times. So the total lapping times is 6. This type of lapping can ensure all the three plates achieve good flatness and similar sand embedded effect. But it always take a long lapping time and much more cost.

 二板互研法：也叫子母板压法，这种方法是只用两块研磨平板一上一下互研。用这种方法研磨压砂结果是，两块平板的平面度基本吻合，上面平板的平面度凹，下板的平面度凸，并且下板的压砂效果要比上板的好。由于上板中间凹，不容易修理量块，一般不用上板，只用下板这一块平板。

Two-piece Lapping Technique:

This type of lapping just require two plates to grind mutually. Embedded sand by this method will ensure the flatness of these two plates are coincided. The flatness and embedded sand effect of lower plate are better than the upper one. So we just use the lower plate.

 所以研磨平台的研磨方法一般选择嵌砂形式的三板互研法，碰到只定做一块非标型号的研磨平板时为了降低成本通常会选用二板互研法。

研磨的详细加工步骤及分类可参照“表面处理-研磨加工”

So mutually lapping in three plates is the common used lapping method for Lapping Surface Plate. But if only one piece of non-standard custom-made Lapping surface plate is required.   Two Piece Lapping Technique will be chosen, in order to reduce the cost.