Thread plug gages are fascinating products when you consider the technical details that go into their manufacture and the precision they embody. To some, they look like fancy bolts and are treated accordingly. 

Digitalization has changed our world as the internet and modern technology continue to shape the manufacturing industry. For example, the vision of Industry 4.0 shows that production systems and machines are required to be flexible and adapt with continuously changing manufactured products. That means production will be more individualized, flexible, and faster. 

The role of metrology is shifting. This is especially true in modern industrial settings and for increasingly exacting applications. Once perceived as a necessary evil residing in the quality control department validating the integrity of finished parts and components, today metrology is viewed more as an enabling technology that truly adds value.

This situation pops up quite regularly when a relatively simple feature such as the diameter of a hole in a machined part doesn’t appear to be right when the part is at the assembly stage of manufacture. Like similar disputes, the finger pointing begins and compromises are made but the problem doesn’t go away. 

My work in inspection, and as a quality management system auditor, provides numerous opportunities to acquire knowledge. It also provides areas of risk for ensuring valid and reliable results. 

In this article, I wanted to go beyond the simple go/no go measurements that most air gaging is used for. Air gaging is a highly effective and efficient way for measuring these simple diameter requirements. It is also extremely repeatable on tight tolerances, but for this article, I wanted to focus on using air gaging to measure form requirements such as roundness, flatness, perpendicularity/squareness, taper, straightness, matching, and others. 

Our Introduction to Surface Roughness Measurement guidebook is an excellent initiation to noncontact surface roughness measurement. It offers practical information on various topics to help make roughness measurement easy and efficient.