Experts agree that, among other tools, digital twins are emerging as stars of smart factories. These are 3D duplicates of parts, products, and buildings.

For most students, measurement and GD&T is a new subject for them. I get the opportunity to review the basic concepts each year. Let's review some of the elements of geometric dimensioning and tolerancing.

GD&T may sound like a complicated or difficult topic, however, understanding it can make your parts cheaper to produce. 

In the longest-lasting version of the hypothetical situation, a hungry donkey is placed equidistant between two identical bales of hay. Paralyzed with indecision as to which bale to choose, the donkey will inevitably starve to death.

It is time to make GD&T much easier to use correctly. Here, then, are a number of examples of confusing Y14.5 Standard terms and definitions, along with recommended improvements.

English actor and author Alan Bennett once said, “We started off trying to set up a small anarchist community, but people wouldn’t obey the rules.”

In Geometric Dimensioning and Tolerancing (GD&T) there has been a long-standing conflict between the worlds of specification and measurement. The goal of specification is to ensure that components will function; the goal of measurement is to ensure that manufactured components meet those functional requirements. 

There is a long-standing practice in the computer aided inspection industry that includes CMMs to report in-tolerance values in green and out-of-tolerance values in red.

Those of us on the march towards Quality 4.0 in our manufacturing companies are grappling with the challenge of producing high quality parts with a minimal investment of time and resources into new inspection methodologies. 

Most quality technicians have been exposed to and probably use geometric dimensioning and tolerance (GD&T) information in their day-to-day work duties.