The International Organization for Standardization (ISO) publishes a group of standards, known collectively as the Geometrical Product Specifications, or ISO GPS Standards, and the American Society of Mechanical Engineers publishes the ASME Y14.5 Standard. There are two main standards for Geometric Dimensioning and Tolerancing in use today. Knowledge of the GD&T standard that your company uses is essential to ensure that drawing information is being interpreted properly.
This concept is known as standardization, and it is just as important for GD&T as any other language. One way to ensure this common understanding is by publishing a document describing the proper use of the language. In order to communicate accurately in any written language, the writer and the reader must share the same understanding of the symbols and structure of that language. Geometric Dimensioning and Tolerancing, or GD&T for short, is a language of symbols used to communicate information on technical drawings. This article provides an in-depth look at of the contents, history, and purpose of the standard. ASME Y14.5 is an established, widely used GD&T standard containing all the necessary information for a comprehensive GD&T system.
