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Category: GD&T & Print Reading Basics

Articles related to reading engineering drawings and interpreting GD&T on the prints

Surface Finish and Flatness

by Crystal Bemis on May 15, 2023.

Surface finish and flatness both limit the amount of variation in a surface – one at the micro level and one at the macro level. Is it permissible to call out both on the same surface?

Virtual Condition vs Tolerance Zone

by Crystal Bemis on May 9, 2023.

In our video question line, our GD&T instructors answer questions submitted by our students. In this video, we answer the question, “Is the Virtual Condition the same as the Tolerance Zone?”

Chamfer Dimensioning

by Crystal Bemis on November 10, 2022.

A chamfer is an edge feature commonly seen on part drawings, and consists of an angled cut on an internal or external edge of a part.

Fillets & Rounds

by Crystal Bemis on November 10, 2022.

Fillets and rounds are both radial edge features, with fillets applied to internal edges and rounds applied to external edges.

Break Edges Note

by Crystal Bemis on November 10, 2022.

“Break all sharp edges and remove all burrs,” is a common drawing note used to notify the manufacturer that the sharp edges and burrs produced by the manufacturing process must be removed from the part.

Knurling

by Crystal Bemis on September 19, 2022.

Knurling is a process used to create a pattern on the surface of a material by displacing or deforming the surface.

How Tolerances Impact Machinists?

by Peter Jacobs on August 8, 2022.

Precision tops the list of priorities in CNC machining since being off by a few thousandths is enough to cause serious errors. While no machine yields a 100% accuracy rate, specific approaches have been undertaken to manufacture components efficiently and economically.

Keyseats and Keyways

by Crystal Bemis on August 1, 2022.

A keyed joint is used to ensure orientation or restrict rotational movement between parts, as in the case of joining a shaft with a coupling. We discuss how a keyed joint is made and inspected in this article.

Restrained Condition Note

by Jason Richter on June 9, 2022.

Some parts, such as those made of rubber or sheet metal, may fail inspection due to deformation from gravity if left in their "free state." This can be prevented by invoking a "restrained state."

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.

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...

The Datum Reference Frame

by Crystal Bemis on April 4, 2022.

What is a Datum Reference Frame? Datums are used in Geometric Dimensioning and Tolerancing drawings to create a reference system for inspecting a manufactured part. This reference system is called a Datum Reference Frame (DRF)....

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....