The process characteristics and mechanical properties of the material of the part roughly determine the type of blank. For example, cast slabs of cast iron parts; commonly used bars for steel parts with simple shapes and low mechanical properties; for important steel parts, forgings should be selected for good mechanical properties; cast steel should be used when the shape is simple Pieces. The material is complex and the mechanical properties are not high. The common profiles or slabs of non-ferrous metal parts can be used.
Most of the blanks of large and simple parts are sand casting or free forging. The blanks with complicated structure are mostly cast, the blanks of small parts can be die forgings or pressure, and the blanks of steel parts are mainly used for forgings; if the diameter of the steps is not very large Can be used on bars; if the dimensions of each step vary greatly, forgings should be used.
When determining the billet, it is necessary to combine specific production conditions, such as the actual level and capacity of on-site production, the possibility of outsourcing, etc., otherwise it is not realistic.
In order to save materials and energy, and improve the efficiency of machining, casting methods and materials such as precision casting, precision forging, cold rolling, cold extrusion, powder metallurgy, profiled steel and engineering plastics should be fully considered. In this way, the amount of machining can be greatly reduced, even without machining. The economic benefits are very significant.