Our country is casting a big country, the domestic casting serious overproduction 750kn bollard, but our cast serious excess capacity refers to the country's low-end casting overcapacity, China's high-end casting production is difficult to be satisfied market needs, Thus, China's casting industry needs to produce low-end castings can be converted into high-end casting production capacity, promote the progress of the casting industry in China. Solving method of casting shrinkage defects, the most fundamental starting point is the "thermal equilibrium." The methods are: (1) at the thickest section of the machine tool castings and thermal structure formation, the implementation of rapid solidification, artificially basic balance throughout the machine casting temperature field. Inside and outside the cold iron bollard case, the local use of heat storage capacity of zircon sand bollard, chromite sand or special coatings. (2) a reasonable process design. Runner in the machine tool castings Pu wall opposite, and scattered more hours. So early into the thick of the lead solidified molten metal, solidified thin wall, so throughout basic equilibrium solidification. Casting machine for uniform wall thickness, using a plurality of inner runner and vents. Runner and more dispersed and uniform 1000kn bollard, and the overall heat balance. And many fine pores, ie unobstructed exhaust cooling effect was underway. (3) changes in the position of the runner (4) selection of heat storage capacity of the molding material, which is the production of anti-wear products with the EPC is extremely important! Chromite sand quartz sand to replace the heat build small sand other species, will achieve good results, pouring Bi microseismic better! 250kn bollard, bollard, Chen Hua machinery provided by China Machinery Co., Ltd. Qingdao Chen. Qingdao Hua Chen Machinery Co., Ltd. (www.qdchenhua.com) strong, credible, in Qingdao, Shandong CNC machine tool industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead Chen Hua machinery and you hand into the brilliant, for a better future!