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.

Beyond Symbols: Fluency in GD&T Decreases Cost

Due to the complex nature of the geometric dimensioning and tolerancing (GD&T) standard, a company’s bottom line profitability can be affected as a result of reading and interpreting errors. Users who have a lack of knowledge concerning the rules, symbols, conventions, and associated terminology of GD&T are more likely to make incorrect decisions.

 

Render of a projected tolerance zone

One such area where a deficit in GD&T language fluency and comprehension can impact manufacturing is in the prototyping process. Situations where a limited understanding can affect this crucial process include the following:

Ineffective design: Designers who do not fully understand the concepts of GD&T may not include GD&T on a print where it would be beneficial. As a result, the part is now much more difficult to manufacture as required information, such as position tolerances, was not provided to ensure the part met fit, form, and function.

Inaccurate manufacturing: Even when GD&T is effectively provided on a print, it may not be understood by the manufacturing team. As a result, there is a higher chance that the part will not be manufactured to the print’s requirements, thus impeding the assembly process. Inaccurate manufacturing means wasted materials, time, and money.

Increased timeline: A limited understanding of GD&T in design, manufacture, or both can lead to multiple back and forth cycles in the prototyping process. With every additional cycle, the time it takes to bring the part into production increases, causing the prototyping timeline to grow longer. Longer timelines equal higher costs, which will ultimately affect bottom line profitability.

The inability to understand and interpret GD&T at any stage of development can have a huge effect on a company’s track to production. Therefore, it is essential for individuals within an organization’s design and manufacturing teams to all be well versed in the language of GD&T in order to have the greatest potential for success.

In the next installment of our GD&T series, we will discuss how an incomplete understanding of GD&T can impact product quality. We at THORS are also happy to announce that our GD&T Fundamentals course has launched!


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.

Lack of GD&T Knowledge Can Impact Your Bidding Process

As a complex standard, geometric dimensioning and tolerancing (GD&T) can lead to reading and interpreting errors. Users who do not have the prerequisite print reading knowledge and ability to see in 2D and 3D space will have an increased difficulty in acquiring the necessary GD&T language fluency. As a result, potential disconnects can occur between the design, manufacture, and inspection of parts, all affecting a company’s bottom line.

Datum Status in Feature Control Frame
Engineering drawing illustrating complex datum reference frames.

One critical area in which a lack of GD&T knowledge can be detrimental to an organization is in the bidding process. Ways in which a limited understanding of GD&T can affect cost estimating includes the following:

Underbidding: Individuals involved in cost estimating who do not understand GD&T could potentially underbid as a result of their lack of knowledge. A limited level of GD&T fluency can cause individuals to undervalue the requirements necessary to make the part. As a result, the responsibility is now on the manufacturing team to make sure the part is manufactured correctly within cost, a task they may not be able to execute.

Overbidding: On the other hand, individuals involved in cost estimating who do not understand GD&T could also potentially overbid due to their lack of knowledge. In this situation, their limited language fluency may cause them to panic at the sight of the GD&T-related symbols, making them add cost. This additional cost arises from the belief that GD&T increases the time it takes to manufacture the part. As a result, the company could lose the bid for a product they could have manufactured. If they do win the bid, they may have made it easy on themselves to manufacture the part; however, they still may not realize how GD&T is going to help make the part more profitable.

In the bidding process, both underbidding and overbidding have their own ramifications. Whether a bid is won but undervalued or lost where there could have been profit, both realities affect a company’s bottom line profitability. It is in these crucial situations where having a full comprehension of GD&T helps organizations and individuals have the greatest potential for success.

In the next installment of our GD&T series, we will take a closer look at the impact of GD&T on the prototyping process. We at THORS are also happy to announce that our GD&T Fundamentals course has launched!


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.

GD&T: 3 Factors that Affect Understanding

Geometric dimensioning and tolerancing (GD&T) is a complicated and complex standard that can lead to reading and interpreting errors. On drawings, GD&T is used as a point of reference in order to easily and effectively manufacture products that meet the fit, form, and function requirements of the part. However, due to the complex nature of the standard, GD&T can be incredibly difficult for users to understand and interpret, potentially leading to a disconnect between the design, manufacture, and inspection of parts.

Datum Reference Frame Constraining Part Movement
Render of a datum reference frame fully constraining a part in all degrees of freedom.

To better comprehend why GD&T is such a difficult concept, the following are common factors that can limit one’s understanding and interpretation of GD&T:

Prerequisite knowledge: GD&T is an advanced-level concept that assumes the user has a full understanding of the rules, conventions, symbols, and associated terminology of print reading. Users who have not mastered the basic concepts found on a drawing are woefully unprepared to understand the complexity and technical intricacies of GD&T.

Language fluency: In its simplest form, GD&T is a language comprised of symbols used on prints that offer an enhanced version of a drawing in order to clearly convey the design intent for the part. Thus, as a language, there are levels of fluency a user must acquire. Until a user is fully fluent in the language of GD&T, much like a native speaker in their mother tongue, they will not fully comprehend the dynamics and relationships between the part’s features expressed on a print.

2D vs. 3D perspective: In addition to the prerequisite knowledge and levels of language fluency, a user must be able to mentally conceptualize the relationships expressed on a drawing between the features of a part. Individuals who are not familiar with print reading and how a two-dimensional drawing translates to a three-dimensional part will find GD&T incredibly difficult to navigate and elusive to grasp.

Due to the limitations imposed by the standard on the understanding and interpretation of GD&T, the following crucial areas in an organization could be affected:

  • Bidding process
  • Prototyping process
  • Product quality

Bottom line profitability can be drastically affected by issues in any one of these critical areas. However, organizations and individuals who dedicate themselves to mastering the basics of print reading, developing their GD&T language fluency, and shaping their 2D/3D perspective have the greatest potential for understanding this fundamental industry concept.

In the next installment of our GD&T series, we will take a closer look at the impact of GD&T on the bidding process. We at THORS are also happy to announce that our GD&T Fundamentals course has launched!


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.