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：所謂三板互研法是指三塊平板互相之間依次互研，并且每塊平板只能當下板兩遍，實際共研磨6遍。使用這種方法壓砂的好處是，三塊研磨平板的平面度都很好，三塊研磨平板的壓砂效果基本一樣，并且三塊研磨平板都可以使用，不用經常壓砂，缺點是加工時間長且每次加工必須制作三塊相同的鑄鐵平板才能完成整個加工，也就是說制作一塊研磨平板的成本和制作三塊研磨平板的成本是一樣的。

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：也叫子母板壓法，這種方法是只用兩塊研磨平板一上一下互研。用這種方法研磨壓砂結果是，兩塊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，并且下板的壓砂效果要比上板的好。由于上板中間凹，不容易修理量塊，一般不用上板，只用下板這一塊平板。

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.

 所以研磨平臺的研磨方法一般選擇嵌砂形式的三板互研法，碰到只定做一塊非標型號的研磨平板時為了降低成本通常會選用二板互研法。

研磨的詳細加工步驟及分類可參照“表面處理-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.