Precision casting dimension accuracy, layout, material susceptible to casting, molding, shell making, roasting, casting, such as the impact of these aspects, specific as follows:(1) casting layoutCasting wall thickness, contraction rate, etc., both of which is higher than involvement, says casting wall thickness was large, the contraction rate is big, on the other hand, on the other hand.(2) materialRefers to the carbon content in the material, as usual, the higher the carbon content, the line contraction rate is smaller, conversely, on the other hand.