Ductile its excellent performance in use can sometimes replace the expensive cast steel and forged steel, widely used in machinery manufacturing industry. International metallurgical industry in the past has been that the British invention of ductile iron in 1947. Some Western scholars even claim that there is no means of modern technology, ductile invention is unthinkable. Taigu Chang foundry in order to meet the conditions of use of these changes, many of the existing ductile iron grades, provides mechanical properties and rational can kiss a very wide range. Taigu Chang introduce you to the covers of classification: Currently grate covers well the market can be divided into cast iron covers, cement covers, resin covers, polymer covers, covers from the point of view of the same quality, strength cast iron far It covers over other materials, in addition to a large cement covers and resin covers for temperature and humidity changes when large temperature difference, the covers, the influence of humidity, the cement covers and resin covers prone to natural phenomena crushed, even without crushing, ductile covers, and then subjected to a load when the intensity is much lower, immediately becomes broken, double covers, cement covers and resin covers the life is far shorter, generally 1 to 2 years, increasing the cost of disguise. Concrete covers | Chang in foundry (certified) | manhole covers on by Taigu Chang foundry. Taigu Chang in foundry (www.sxcnzz.com) is Jinzhong, machining leaders, over the years, the company implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. In Chang in foundry leadership with the staff warmly welcome all inquiries negotiations to create Chang foundry in a better future.