Improving Product Quality by Increasing Your GD&T Fluency

The geometric dimensioning and tolerancing (GD&T) standard can cause reading and interpretation errors due to its complex nature. When an individual’s ability to comprehend and utilize this fundamental industry standard is limited, potential costly oversights and inaccuracies can occur, ultimately affecting a company’s bottom line.

part call out in engineering drawing
Render explaining form deviation permitted per Rule #1

A significant area of manufacturing that can be impacted by a lack of GD&T language fluency and comprehension is product quality. Ways in which a limited understanding can affect this quality issue include the following:

Design vs. manufacture: When a designer has an incomplete knowledge of GD&T, they may not include GD&T on a print where necessary. As a result, the manufacturing team now must struggle to produce the part without the guidance that GD&T would have provided. If the manufacturing team also has a limited understanding of the GD&T on a print, the part may not be manufactured correctly, making it difficult to assemble. In any of these situations, an increase in scrapped parts may occur.

Inspection errors: A poor grasp of GD&T can also dramatically affect the inspection process. When inspectors do not have a clear comprehension of GD&T and the relationships conveyed between the features on a part, good-quality parts may be scrapped and bad-quality parts may pass inspection. The ramification of both situations could have a significant impact on an organization’s costs.

All areas of design, manufacturing, and inspection need to know GD&T so that it can be applied consistently throughout an organization. In situations where these respective teams are not equally in alignment, quality is compromised, further affecting the bottom line profitability. Uniform and accurate interpretation of GD&T results in a highly profitable process that has less rework and faster cycle times. Individuals and organizations who have a full comprehension of GD&T have the greatest potential for success.

This final installment concludes our GD&T series where we discussed the impact of GD&T understanding on the manufacturing process. Ready to become fluent in GD&T? Check out our GD&T Fundamentals course, and contact sales to set up a trial.


Kavita Krishnamurthy is an ASQ certified Six Sigma Black Belt with over 15 years of experience in the field of process improvement, manufacturing engineering, and quality management in the automotive and gear industries. She is also the subject matter expert of our GD&T Fundamentals course.

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