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The surface of precision drawing stamping parts does not have the defects of die casting parts. The shape of the stretched part should be simple and symmetrical, the mouth should be allowed to rebound slightly, and the side wall should be allowed to have a technological slope. The wall thickness of the wall part of the cylinder generally has the phenomenon of being thick at the top and thin at the bottom. The shape of the precision drawing stamping parts should be as simple and symmetrical as possible, and the workpiece should be drawn as much as possible; for the workpiece that needs to be drawn multiple times, under the premise of ensuring the necessary surface quality, the internal and external surfaces should be allowed to exist in the deep drawing process. Traces; on the premise of ensuring the assembly requirements, a certain slope of the side wall of the drawn part should be allowed; the dimension of the drawn part should indicate the guaranteed external dimension or the internal dimension, and the internal external dimension cannot be marked at the same time. For deep drawing parts with steps, the dimension in the height direction should generally be based on the bottom. If the upper part is the reference, the height dimension is not easy to guarantee; apply dry film lubricant on the surface of the concave die (the main ingredients are: nitrocellulose, oily alcohol Acid resin, plasticizer, extreme pressure agent and other additives) to reduce the frictional resistance between the material and the mold surface during the deformation process, so that the material can flow more easily from the deformation zone to the force transmission zone. Combining the final two processes in the original process (ie forming and drawing, flanging process), and integrating them into one process (forming and flanging), so that the processing steps of the precision drawing part are not increased, which is also effective Control the processing cost. Reasonable rounded corners of the convex and concave molds, adding appropriate heat treatment procedures and applying lubricant on the surface of the concave mold, etc., can improve the success rate of metal drawing parts forming. Metal tensile parts are widely used in various fields of life, including some electronic devices, leaf springs, auto parts, decorative materials, etc. The shape of precision drawing stampings should be simple and symmetrical, the mouth should be allowed to rebound slightly, and the side wall should be allowed to have a technological slope. The wall thickness of the wall part of the cylinder generally has the phenomenon of being thick at the top and thin at the bottom. Hardware tensile parts processing manufacturers propose to pay attention to the dimensions on the design drawings of the tensile parts. Due to the different stresses on the tensile parts, the thickness of the material after stretching changes. Generally speaking, the center of the bottom maintains the original thickness, the material at the bottom rounded corners becomes thinner, the material at the top near the flange becomes thicker, and the material at the rounded corners around the rectangular stretched piece becomes thicker. Standard method for product dimensions of precision stretched parts: When designing stretched products, the dimensions on the product drawing should clearly indicate that the external dimensions or internal dimensions must be guaranteed, and the internal and external dimensions cannot be marked at the same time. Marking method of drawing part dimensional tolerance: the inner radius of the concave-convex arc of the drawing part and the height dimensional tolerance of the once-formed cylindrical drawing part are the double-sided symmetrical deviation, and the deviation value is the national standard (GB) 16 accuracy standard Half of the difference, and prefixed with ±.