Downloaded from https://www.everyspec.com READIN GS REAOING141 .001 .004 ,.004 .000 Figure 5-17. Effect of cocked center lines on dial readings Dependent locational tolerances should be used, center of the hole may vary. The large circles rather than toleranced coordinates, when dimen- show the positions of the minimum holes at the sioning the location of holes. Figure 23A of positions of maximum variation permitted by Drawing 30-1-7 explains why this Is desirable, coordinate dimensions.
In order to permit the but further explanation is given in the following manufacturer his full tolerance, the gaging pin paragraphs, since production and inspection are would necessarily be of the shape shown by the vitally interested in the method used. four arcs that are drawn in heavier lines. Since the cost of making simple locational gages with Figure 5-18a shows a portion of simple part pins of that shape would be prohibitive, thegage with a single hole, the location of which is fixed engineer will design the gage with a round pin. by coordinates. Figure 5-18b is an enlarged To ensure that only conforming parts will be view of 5-18a.
The square in the center shows accepted, the pin would necessarily be of the the permissible tolerance zone in which the size shown by the dashed circle. The .500 .5o oo .500.00 Cy . 50 +..00 MIN MAX. Figure 5-18. Effect of hole location of coordzinates on production and inspection 5-17