Free state variation is a term used to describe distortion of a part after removal of forces applied during manufacture. This distortion is principally due to weight and flexibility of the part and the relca.sc of internal stresses resulting from fabrication. A part of this kind, for example, a pan with a very thin wall in proportion to iLs diameter, is referred to as a nonrigid pan. In some cases, it may be required that the pan meet its tolerance requirements while in the free state. See Fig. 6-53. In others, it may be necessary to simulate the mating pan interface in order to verify individual or related feature tolerances. This is done by restraining the appropriate features, such as the datum features in Fig. 6-54. The restraining
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