Our country is in the 1950s and the beginning of the sixties the investment casting used in industrial production. Later this advanced casting process has been tremendous development, have been widely used in the aerospace, automotive, machine tools, ships, internal combustion engines, gas turbines, telecommunications equipment, weapons, medical equipment and tools and other manufacturing industries, as well as for process Manufacturing and crafts of. The so-called investment casting process, it simply is to use fusible material (such as wax or plastic) fusible model (referred to as the melting mold or model), which is coated in several layers of a special fire-resistant coating of iron castings, after drying and after hardening to form a whole shell casting, and then steam or hot water from the shell model of melt away, and then placed in the sand box shell, filled with dry sand around it in shape, and finally cast into the roaster the high temperature roasting, mold or shell fired by mold casting, in which molten metal is poured to obtain castings (such as the use of high-strength shell, and the shell may not have direct roasting shape after stripping). Casting Casting reflect actual figure is the size, shape and pattern technical requirements, it is casting production, mainly based casting inspection and acceptance; cast figure generally by casting manufacturers in the product process development stage, according to the product drawings to sell castings, the product map increase on the basis of the draft angle, allowance, not cast out holes, slots, and the size of the drawings and other technical requirements, as foundry, castings inspection and acceptance of the product, or on customer requirements and product plans have sent to the cast together manufacturers as the basis for product acceptance. Painting (1) in the casting indicated by a thick solid line in FIG casting contour; represents the shape of the part with a thin two-dot chain line; between the thick solid line and two-dot chain line denoted thin allowance value; in cross-section The figure represents allowance or not cast holes, slots, etc. with the grid lines. (2) the size of the labeling method mostly part size as a benchmark; mark the actual size of the casting parts diagram; allowance (including draft angle), etc. are marked out in parts of the size of the line; cast figure also apply Symbols marked parting surface. (3) should be marked on the map casting tolerance, hardness, does not allow casting defects and other technical requirements and test methods. Small castings | Chen Hua machinery (certified) | casting provided by China Machinery Co., Ltd. Qingdao Chen. Qingdao Hua Chen Machinery Co., Ltd. (www.qdchenhua.com) is Qingdao, a leader in CNC machine tools over the years, the company implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. Chen Hua Machinery leadership in the staff warmly welcome all inquiries negotiations to create a better mechanical Chen Hua future.