What are the risks of reliance on the automatic specification selection feature in CAD systems

Excessive reliance on the automatic specification selection feature in many CAD systems at the design stage can be risky, says Challenge Europe. 

These systems match physical dimensions but frequently neglect the materials or stock availability. This is also the case where, for example, a standardised component is requested, but in a material not covered by that standard.

This focuses on the need to consult a specialist fastener supplier, especially regarding subcontract assemblies, since it may be that they cannot actually comply with the original drawing. In turn this has a major time implication in getting changes made when compliance is impossible.

A good example is a case where it was found necessary to take a superior product and downgrade it at extra cost, eg a washer to a certain specification, custom specified with a wide manufacturing tolerance where actually a normal spec washer would have been suitable but not meet the spec. 

The solution was to take standard washers and drill them out at extra cost. Especially where small quantities are concerned, this can be a major issue.

The solution has been found to lie in developing trusted supplier relationships where consultation at an early stage can bring these issues to light. 

Not only will such a supplier have an extensive knowledge of materials and finishes – they will also be in a position to advise on stock availability and alternative ways of meeting custom requirements. 

For example, it may not be necessary to custom produce from scratch where a standard item with treatment or other adaptation may be suitable, more readily available and cheaper.