In technical drawing, a basic dimension is a theoretically exact dimension, given from a datum to a feature of interest. In Geometric dimensioning and tolerancing, basic dimensions are used to communicate the critical design dimensions of a part. Basic dimensions represent an ideal case and as such, have no tolerance. To facilitate manufactureability, a feature control frame is often used to assign a dimensional tolerance to the feature that is referenced in by the basic dimension. Chained basic dimensions do not create tolerance stack up. Proper tolerance must be inferred by Datums referenced in the feature control frame, and not by dimension arrows or start points.
Basic dimension are denoted by enclosing the number of the dimension in a rectangle.
Famous quotes containing the words basic and/or dimension:
“It seems to me that our three basic needs, for food and security and love, are so mixed and mingled and entwined that we cannot straightly think of one without the others. So it happens that when I write of hunger, I am really writing about love and the hunger for it, and warmth and the love of it and the hunger for it ... and then the warmth and richness and fine reality of hunger satisfied ... and it is all one.”
—M.F.K. Fisher (b. 1908)
“Le Corbusier was the sort of relentlessly rational intellectual that only France loves wholeheartedly, the logician who flies higher and higher in ever-decreasing circles until, with one last, utterly inevitable induction, he disappears up his own fundamental aperture and emerges in the fourth dimension as a needle-thin umber bird.”
—Tom Wolfe (b. 1931)