Geometric Dimensioning & Tolerancing (GD&T) Workshop 2026

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About the Workshop

Organized by the Smart Manufacturing and Lean Systems Research Group.

To better define a product, geometric dimensioning and tolerancing (GD&T) is often used as a symbolic way to show tolerances on mechanical drawings. This one-day course covers the GD&T system per ASME Y14.5-2009, including why it reduces costs, how to interpret the symbols, and how to apply these tolerances correctly. Participants will learn the basic definitions and rules, the importance of datums, the meaning of each tolerance, and the impact on manufacturing and gaging. The class is a lecture format, with ample opportunity for questions, and participants are welcome to bring sample prints (with or without GD&T already applied) to discuss with the instructor during breaks or after the class.

Registration Fee: $40 includes Lunch Buffet at LTU Cafeteria by Aramark (Pre-registration is required)

Certificate of Accomplishment will be provided.

Continue Education Unit (CEU) / Professional Development Unit (PDU) Credits will be available.

A spiral binding book for GD&T will be provided.

Speaker

John-Paul Belanger
President of Geometric Learning Systems
Rochester Hills, Michigan

John-Paul Belanger is president of Geometric Learning Systems, based in Rochester Hills, Michigan. He is certified as a Senior-Level GD&T Professional by the American Society of Mechanical Engineers. Mr. Belanger has been a full-time GD&T instructor and consultant for 20 years, traveling throughout North America and Europe helping corporate groups implement GD&T properly in design, manufacturing, and inspection activities. He holds a degree in aerospace engineering from the University of Michigan, specializing in aircraft design and safety.

Learning Objectives

By attending this seminar, you will be able to:

• Explain the benefits of geometric tolerancing.
• Identify datum features and determine their order of precedence.
• Identify and interpret each of the characteristic symbols.
• Describe the material condition modifiers and how "bonus" tolerance occurs.
• Correctly interpret GD&T feature control frames, and explain the impact on manufacturing and inspection.

Who Should Attend

This course is ideal for anyone who has a need to apply or interpret geometric tolerances on a product print. Product engineers, manufacturing engineers, CAD designers, quality inspectors, and other engineering and manufacturing personnel will all benefit from becoming fluent in GD&T.

Prerequisites

Participants should have knowledge of basic blueprint reading.

Topical Outline

Drawings and Dimensioning

• Importance of engineering drawings
• The need for geometric dimensioning and tolerancing
• Quality issues – how GD&T fits into other standards
• GD&T standard: ASME Y14.5-2009

Introduction to GD&T Symbols and Terms

• Definitions – feature, feature of size, actual mating envelope
• Material conditions – MMC, LMC, RFS
• Reading a feature control frame

Rules and Concepts of GD&T

• Rule #1 – Size controls form
• Rule #2 – Implied RFS
• Basic dimensions
• Virtual condition
• Bonus tolerance

Form Tolerances

• Flatness
• Straightness
• Circularity
• Cylindricity
• Straightness and flatness applied to a feature of size

Datums

• Purpose of datums in GD&T
• The datum reference frame – primary, secondary, tertiary
• Feature-of-size datums
• Datums with the “M” modifier
• Compound datum features and Datum targets
• How to select datums for a part

Profile Tolerances

• General definition of profile
• Profile of a line
• Profile of a surface
• Profile with datum references
• Composite profile control

Orientation Tolerances

• Perpendicularity
• Angularity
• Parallelism

Location Tolerances

• Definition of “true position”
• Application of position at RFS
• Using position with MMC or LMC
• Composite position control
• Projected tolerance zone and symmetry
• Concentricity – why it is not recommended

Runout Tolerances

• Difference between runout and other circular controls
• Circular runout
• Total runout

Wrap-up and Course Evaluation