• 1-888-TEC-EASE
  • Outside USA: 1-716-785-6015
Free Tec-Ease Mug GD&T Textbooks GD&T Training GD&T Public Seminars GD&T Computer Based Training GD&T Reference Material
What are the rules?
(In accordance with Y14.5M-1994 standard)

PDF of this Tip

The rules of geometric dimensioning and tolerancing have changed over the years.  In addition, the meaning of such symbols as runout, total runout, concentricity and symmetry have changed.  You cannot go by the drawing date since many companies may delay adoption of a new revision for several years.  Unfortunately, the drawing doesn’t always state the revision to use when translating the symbols into plain English.  Often you can determine which Standard was used by observing differences in the callouts.  Your choices of Y14.5 standard revisions are 1966, 1973, 1982 and 1994.  Here are a few things to look for when determining which revision of the Standard to use.

Back to Tips Tip added Nov 1997