GD&T Articles

by Seth Elder on November 12, 2020.

The video below is in response to a question that we received on our question line from Ash.   The question is as follows: “I regularly see drawings where spacing between a pair of holes is critical, but not so much the position of the pair as a whole.  Often the dimension to the first hole…

by Crystal Bemis on November 6, 2020.

Everyone understands the simple plus or minus tolerances of coordinate dimensioning. So why use GD&T instead? Here are four reasons that GD&T has an advantage over coordinate tolerancing… What are the advantages of GD&T vs. Coordinate Tolerancing? Coordinate dimensioning is easy to read and understand. It’s the way most of us have learned to create…

by Seth Elder on October 29, 2020.

The video below is in response to a question that we received on our question line from Jeff.   Jeff asked us if concentricity is always equal to half of the runout value.  ASME Y14.5 defines concentricity as the requirement where the derived median points of all diametrically opposed elements must align with the axis of…

by Brandon John on October 20, 2020.

There are many great reasons why engineers & designers benefit from knowledge of Geometric Dimensioning & Tolerancing (GD&T). But today, we want to share with you just one reason that is particularly interesting. Even though GD&T is simply a method of communicating inspection criteria & dimensional specifications on 2D drawings, learning to use it can…

by Seth Elder on October 12, 2020.

In this article, we explain the differences between bilateral, unilateral, and unequally disposed tolerances. What is a Tolerance? Tolerances on technical drawings communicate the amount of variation permitted from a target dimension.  The allowable variation can be visualized as a zone surrounding the ideal surface of the part – what is called “true profile.”  For…