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Author: Crystal Bemis

Position Tolerance vs “True Position”

by Crystal Bemis on June 8, 2022.

Though many people refer to the GD&T Position symbol as "True Position," they are not the same thing. Read on to learn the difference between Position and True Position and how they work together to define the position of a feature.

The Problem with Reporting Basic Dimensions

by Crystal Bemis on April 28, 2022.

Basic Dimensions are theoretically exact dimensions that define the ideal exact location and orientation of surfaces and features of size. A basic dimension is shown on a drawing as a dimension inside of a box, and it will have no...

Why Use GD&T?

by Crystal Bemis on April 27, 2022. (sticky)

We get a lot of questions from students asking why they would want to use Geometric Dimensioning and Tolerancing (GD&T) over coordinate dimensions. Some believe that using GD&T will result in tighter tolerances and increase a part’s cost. Others believe...

The Datum Reference Frame

by Crystal Bemis on April 4, 2022.

What is a Datum Reference Frame? Datums are used in GD&T drawings to create a reference system for inspecting a manufactured part. This reference system is called a Datum Reference Frame (DRF). Datums are derived from datum features. Datum features...

Take our GD&T Skills Assessment Quiz!

by Crystal Bemis on January 28, 2022.

Having a good understanding of Geometric Dimensioning and Tolerancing is very important for anyone working in a mechanical field. GD&T is the language used in design, manufacturing, and quality inspection to communicate on engineering prints. It combines a set of...