The Importance of GD&T
What is GD&T? The Common Language
Geometric Dimensioning and Tolerancing (GD&T) is a discipline developed to communicate engineering configuration from the designer to the manufacturer through engineering drawings. It is used primarily to alleviate misunderstandings and, thus, provide complete and concise meanings to the production team members.
In 1966, industry, the Department of Defense and educational institutions adopted a common American standard dealing with GD&T application and interpretation: American National Standard Institute standard Y14.5.
The latest Dimensioning and Tolerancing standard, Y14.5-2009, was released in 2009. The majority of the GD&T symbology has remained unchanged, however there has been some symbol modifications and additions, and a considerable amount of new material added.
Knowing The Language Is The Key
Geometric Dimensioning and Tolerancing (GD&T) is a language used to communicate engineering configuration from the designer to the manufacturer through a mechanical drawing. When properly applied, GD&T promotes a uniform understanding and interpretation among all persons involved with the drawing.
The universal problem experienced with the Y14.5 standard is the failure to adequately educate the drawing originators, manufacturers, and quality control personnel in a complete understanding of this communicative tool. As a result, both design and manufacturing suffers due to this training oversight. Until GD&T literacy exists in the United States, productivity will suffer, lawsuits will continue, and production costs will not be minimized.
A complete understanding of GD&T is vital for tearing down the walls of misunderstanding.