Technical Education Post

News and Information for Technical Educators

Teaching GD&T as a Native Language

I recently chatted with a colleague who speaks two languages. Spanish is her first language and English is her second. During some of our conversation, I noticed gestures that indicated she was trying to figure out how to communicate her words in English. I asked how she processes her thoughts when speaking in English. She said she thinks in her 1st tongue to speak in her 2nd tongue. Teaching GD&T as a Native Language.

Then it dawned on me. This is the same struggle most people have with GDT. It’s been around for multiple generations. Manufacturers agree it is the universal language for industry. Yet, our trainers and educators teach GDT as a 2nd language. 2nd Language! How can the “universal language of the industry” be secondary?

We, as an industry, need to lead a paradigm shift by taking it from optional learning to native tongue. We’re currently teaching Limit Dimensioning (LD) as the native tongue with all its flaws and then GDT later down the line, similar to learning a second language.  Consequently, learners think in LD to understand GDT. Not only do they struggle with GDT concepts, but they also only understand the parts of it that are relatable to LD, ignoring the rest.

So how do we lead this paradigm shift with GDT? First, we must forget the idea of learning LD first, then GDT later. Rather, GDT should be taught with LD as one language.

Before I get into how we teach GDT, I need to touch on why GDT is so important.

In the past, limit dimensioning worked because the person making Part A of an assembly was most likely also making Part B. Using tribal knowledge and craftsmanship, the person was able to machine both parts to fit and work together as intended.

In today’s world of global mass production, Part A and Part B are most likely not even being made in the same country, much less by the same person. Without GDT to communicate the designer’s intent of the part, we cannot be confident it will be made and inspected correctly. 

In this environment, it’s more important than ever that people in our industry can correctly speak one common language to communicate precisely.

That language is GDT

So how do we ensure GDT is a native part of our manufacturing language? Rather than teaching it secondarily, we need to include it in the entire learning process, and we do this through an approach called “weaving.”

Weaving conditions learner’s critical thinking with GDT even when the primary learning objective is not GDT. It’s as a “wax-on, wax-off” approach. In the movie The Karate Kid, sensei Miyagi and his student Daniel strike a deal: “I will teach you karate. You will do what I say.” But instead of teaching and mastering one move at a time like they do in a traditional dojo, Mr. Miyagi teaches Daniel karate through everyday tasks – cleaning cars, painting the fence, etc… Wax on. Wax off.

The lesson? Karate isn’t a separate discipline you learn at a dojo and apply when needed. It’s a part of your everyday life. This is how we should be teaching GDT to our future engineers, designers, programmers, and machinists. As a part of their everyday life, not something they learn separately and apply when needed.

How to Speak GDT

For that to happen, the first thing an organization needs to do is train their leaders how to speak GDT while teaching other things. GDT should be woven into all coursework. Of course, plan reading, but also programming, CAD/CAM classes, quality assurance, etc. The trick is to find those places in your curriculum where it’s natural to talk about GDT (and LD), then weave! NIMS Geometric Dimensioning and Tolerancing training deepens your knowledge of GDT, teaches you how to find those natural places, and how to weave it into the curriculum you’ve already created rather than create a new one from scratch). Taking this course will change the culture of your organization and make GDT the 1st language of the entire workforce. 

Always learning,




Teaching GD&T as a Native Language

Montez King, Executive Director – NIMS (National Institute for Metalworking Skills)

Leave a Reply

Your email address will not be published. Required fields are marked *

Upcoming Events