Two Critical Conditions . .. L ~_j_ i:== "" :': I 818 SURFACE " S" T GAGE ± .0000


had to be met in order to cast "ready for use" this cobalt base, wear resistant alloy, shoe for a steel mill cutting machine. First, gage dimensions had to be held within tolerance and, second, surface "S" had to be cast flat. Without clearly defining methods for inspection, the operation might have resulted in continuous argument between the producer's inspection and incoming inspection as to what constituted an acceptable part. Misinterpre- tation was avoided, and surface "S" and gage dimensions were cast to size by having the user provide a functional checking fixture which served as a "go" and "no-go" gage.


The Secret Of Success ...


in this part was the realization by the design engineer that he wanted a cast part that worked, regardless of tolerance. This rack and jaw for a hand tool had to fit with and match the operation of other component parts. Tolerances were deliberately left off the drawing dimensions. By making one foundry responsible for producing all mating parts, it was possible for the foundry to adjust its tooling to eliminate improper fit on all the parts. This alloy steel part, hardened to RC 45-50, is an example of fine work that can be done when a foundry has a cooperative designer working with it.


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