If there is a single area where the designer can accomplish the greatest benefit in producibility and economy of manufacture, it is perhaps in communicating effectively with the supplier, using appropriate detailing practices on drawings. Following are a few basic guidelines which can make an enormous difference:

First, select a meaningful datum in the body of the part - passing through hole center, if possible - rather than using an edge or corner of the part. (See dimensioning Practices for Press brake). There are several reasons for this suggestion.

It avoids problems of possible misalignment of the part, distortion from clamping, etc. It allows for more precise measurement by avoiding measurements from edges which may be tapered and therefore dimensionally uncertain. It facilitates accurate inspection and it avoids unnecessary accumulation of tolerances.

Second, on related hole patterns, dimensioning and tolerances should be within this pattern with only one dimension linking to the general datum. Better quality control and function of the product can be expected.

Third, highlight the truly significant dimensions. Critical dimensional relationships can be protected, if they are known.

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