Casting defects classification of technical reasons, generally speaking, there are the following:The first is a design, the design work and bad make its flawed, and the causes of so is stuck a link, when reach this link, tooling manufacture of casting products have defects.Materials and smelting, the second is when the two different defects are inevitable, melting is an alloy of metal and stainless steel products manufacturing, rational shrinkage is larger, the performance of hot crack of the situation will be very big, when the external and internal defects of increasing cases, casting technology can also cause errors.