Geometrical product specification – tolerance values in the sense of form, direction, location and run-out

  • Posted by Gerhard Pramhas
  • On 21. August 2021


Today I want to address the most important topic of a technical orientated business: tolerances.

Every engineer is deeply informed about the word ,,tolerance’’. There is not a single structural component in technical systems and products that can be produced exactly that way the designer plans it.

Endless combination possibilities & variations

While mastery of length dimensions is still reasonably well conceivable, it gets extremely complex in the interaction with other components and with the consideration of fitting accuracy and surface definitions. Thus, combination possibilities & still permitted variations increase endlessly.

,,Make or Buy’’?

The ,,make or buy’’ discussion is ongoing in most companies in the world. The central question is: Do you build your parts yourself or do you buy them?

The question is easily answered by a business economist: You should design components by yourself, derive standard-compliant production drawings from them and look for a supplier who can build and deliver them. Challenges start here. It is nearly impossible to document a design, so that a supplierer can transform ideas correctly and adjust parts 1:1 in your production without any questions. Have you also included these ,,detour costs’’ into your calculation? Is it not cheaper at the bottom line to manufacture in your own factory despite the high personnel costs in Austria? Especially in times like these, should you not be thinking about insourcing instead of giving further valuable manufacturing know-how to your suppliers?

If you want to speak about the topic ,,tolerances’’ in connection with the economic procurement of components with me, please contact me.