GD&T Articles

by GD&T Basics on April 12, 2021.

What is the difference between unilateral and bilateral tolerance in a profile of a surface callout? In this post, Brandon explains the difference and gives examples of how they are used. Profile of a Surface When applying a 3-Dimensional tolerance zone around a surface, usually a curved shape but could be any, the Profile of…

by GD&T Basics on April 6, 2021.

This video is in response to a question that we received on our question line from Amar. Amar’s question is as follows: “If we are given a BASIC radius of 10mm, and on the radius, we are applying a Profile of a Line Tolerance of 0.6mm, what will be the max & min size of…

by GD&T Basics on March 30, 2021.

Orthographic views allow us to represent a 3D object in 2D on a drawing. Orthographic views can show us an object viewed from each direction. How the views are laid out on a drawing depends on whether 3rd angle or 1st angle projection is being used. You can tell which angle projection is used by the symbol…

by GD&T Basics on February 14, 2021.

This video is in response to a question that we received on our question line from Tim. Tim’s question is as follows: “We tend to use true position on threaded holes.  Is this valid?  If so, what is the proper way to measure it, and what is it “actually” measuring?  Is it the true position…

by GD&T Basics on February 14, 2021.

This video is in response to a question that we received on our question line from Jamee.  Jamee’s question is as follows: “For parallelism of a circular feature of size (axis) can you use two surfaces perpendicular to each other (that are both parallel to the feature axis) as datum references within the FCF to…