Positional accuracy refers to the difference in actual positional accuracy between the surfaces of the parts after processing of Huangjiang mold.. 4, the relationship between dimensional accuracy, shape accuracy and positional accuracy Generally, when designing machine parts and specifying the machining accuracy of parts, it should be noted that the shape error trash can mold should be controlled within the position tolerance, and the position error should be smaller than the dimensional tolerance. The items for assessing positional accuracy include eight items: parallelism, verticality, inclination, concentricity, symmetry, position, round runout, and full runout. Level 1 is the highest and level 12 is the lowest. Dimensional accuracy is controlled by dimensional tolerances. The items for evaluating the shape accuracy include six items such as straightness, flatness, roundness, cylindricity, and line outline. The shape accuracy is controlled by the shape tolerance. That is, the important surface of precision parts or parts, the shape accuracy requirements should be higher than the position accuracy requirements, and the position accuracy requirements should be higher than the dimensional accuracy requirements. The shape tolerances are divided into 12 precision grades except for the roundness and cylindricity. Position accuracy is controlled by positional tolerances, and the positional tolerances of each item are also divided into 12 accuracy levels. 2. 3. Shape accuracy refers to the degree of conformity between the actual geometry of the surface of the part after the mold is processed and the ideal geometry. Dimensional accuracy refers to the degree of conformity between the actual size of the part after machining and the tolerance of the part size. In the case of the same basic dimensions, the smaller the dimensional tolerance, the higher the dimensional accuracy. Dimensional tolerances are the allowable variations in the dimensions of the part during mold machining.Main factors affecting the precision of mold processing.The main factors affecting the accuracy of mold processing 1
