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Category: Inspection of GD&T

Articles related to inspection of engineering prints and interpretation of GD&T for inspection purposes

Composite Profile Control

by Crystal Bemis on June 3, 2024.

In this Question Line video, Jason discusses a composite feature control frame controlling profile tolerance. He walks through through the user submitted examples to explain the controls of each frame.

Radial Hole Pattern as a Datum Feature

by Crystal Bemis on May 27, 2024.

In this Question Line video, Jason responds to a question regarding radial hole patterns as datum features. He discusses how to set up the datum reference frame, how the datum reference frame controls degrees of freedom, and how to apply the Maximum Material Boundary.

How to Inspect True Position at an Angle

by Crystal Bemis on April 29, 2024.

When a hole is being controlled with position, the primary datum is often the surface that the hole originates from and the secondary and tertiary datums are perpendicular or parallel to the primary datum. However, this is not always the case. In this video, Jason walks through an example drawing to show us how to inspect a hole that is at an angle with respect to the primary datum.

Measuring Runout and Circularity with V-Blocks

by Crystal Bemis on April 1, 2024.

V-Blocks are popular tools used with manual inspections, but come with a unique pitfall that can impact the accuracy of measurements. In this video, Jason walks through the potential issues associated with using V-Blocks and how they can affect measurements of circularity and runout.

Profile Inspection: Vectors in CMM Measurement

by Crystal Bemis on March 4, 2024.

Coordinate Measuring Machines (CMMs) are essential tools for obtaining precise measurements. However, to ensure accurate measurements, it is crucial to understand how to use them correctly. In this video, Jason explains the importance of recognizing and utilizing appropriate vectors when inspecting a profile or irregular surface with a CMM probe.

Go/No-Go Gaging and Rule #1

by Crystal Bemis on November 14, 2023.

In this Question Line Video, Brandon explains Rule #1 of GD&T (the Envelope Principle) and how Go/No-Go gages are used to verify that Rule #1 is met for a feature of size.

Functional Gaging and CMMs

by Crystal Bemis on September 26, 2023.

In this Question Line video, Jason compares the use of functional gages and CMMs for inspection and discusses benefits and drawbacks of each.

ISO vs ASME Position Tolerance

by Crystal Bemis on August 3, 2023.

“How do I inspect position if my drawing references ISO?” In today’s Question Line Video, Jason looks at a part with a cylindrical hole feature and compares the ASME and ISO standards for controlling the position of that hole.

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."

The Problem with Reporting Basic Dimensions

by Crystal Bemis on April 28, 2022.

In Geometric Dimensioning and Tolerancing, 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...

Circularity, Rule #1, and How to Report

by GD&T Basics on February 12, 2021.

This video is in response to a question that we received on our question line from Amber. Amber asked us if the tolerance value for circularity can be obtained by subtracting the upper limit of...

What is a Profilometer?

by GD&T Basics on February 12, 2021.

Ever wonder how surface finish is measured? For inspection, we use a device called a Profilometer.  In this article, we will show you how profilometers work and highlight their advantages and limitations. What is a...

Basic Dimensions and How to Report

by Brandon John on January 27, 2021.

In this video, Brandon discusses basic dimensions and why they should not be recorded on an inspection report. What Are Basic Dimensions? Basic dimensions are used in Geometric Dimensioning and Tolerancing to describe the theoretically...