The preparation work before sand pressing is very important. What kind of tablet should be chosen first? Which sand pressing method is used? What specifications of sand should be used? There are generally three types of plates for repairing gauge blocks: gray cast iron, high-phosphorus nodular cast iron, and high-phosphorus low-metal nodular cast iron.

 

 

cast iron plate

 

The hardness of the plate is between HB (130～250). The flat plate with lower hardness is used to embed coarse sand easily and is suitable for rough grinding. The surface roughness of the repaired gauge block is relatively low and the surface is white. Using a flat plate with higher hardness, it is difficult to embed coarse sand, and it is easy to embed fine sand, which is not ideal. The surface roughness of the repaired gauge block is high and the color is blue and bright. According to experience, the use of a flat plate with a hardness of HB (180-210) is not only easy to press sand, but also suitable for high-precision precision grinding, especially for gauge block repair.

 

1. There are generally two grinding methods for flat plates: one is the three-plate mutual grinding method. The result of this method is that the flatness of the three plates is very good, and the sand pressing effect of the three plates is basically the same, and the three plates are basically the same. It can be used, and there is no need to press sand frequently, but it requires higher repair technology. The so-called three-plate inter-grinding method refers to the mutual study of the three plates in turn, and each plate can only be placed on the current plate twice, and the actual grind is 6 times in total.

 

2. Another method is the mutual research method of two boards, also called the method of pressing the mother board. This method uses only two plates to grind up and down. The result of this method is that the flatness of the two plates is basically the same, the flatness of the upper plate is concave, the flatness of the lower plate is convex, and the flatness of the lower plate is convex. The sand pressing effect is better than that of the upper plate. Because the upper plate is concave in the middle, it is not easy to repair the gauge block. Generally, the upper plate is not used, and only the lower plate is used. The disadvantage is that the degree of protrusion of the lower plate is not easy to grasp, and only a flat plate can be used. It takes 3 to 4 times to complete the sand pressing, and it takes about 6 minutes each time.

 

Jinggong Measuring Tools Producing Co., Ltd is specializing in manufacturing and exporting all kinds of cast iron products，especially for cast iron floor plates, cast iron surface plates, cast iron clamping plates, cast iron angle plates, cast iron box table and other machine tool castings. Our engineering enables us to design the cast iron plates and tables according to DIN Standards, Indian Standards and Chinese Standards, machining by CNC machine tools and install in the world market.