Geometric Dimensioning & Tolerancing
Professional Development Workshop

Now Enrolling!

Conveniently delivered online, no matter where you are located!

October 4-7, 2021

Geometric Dimensioning and Tolerancing is the universally accepted method of communicating dimensioning requirements on engineering drawings. This workshop will help you understand and use this universal engineering language to communicate the types and amounts of the inevitable variation that parts are allowed to have, per the drawing.

Program Logistics

  • Delivery: 4x 4-hour live, synchronous sessions (16 hours), from 9:00 am - 12:30 pm (ET). 
  • Cost: $1,350 
  • CEUs: 1.4
  • Instructor: Charles A. GIllis, P.E. (bio)
Click here to Register

Course Description & Outline

Intended for practicing professionals who create drawing specifications or read drawings, this course helps students make sense of a topic that some find overwhelming. In a safe learning environment, the key principles are explained and brought down to the real world. More than simply memorizing symbols, students leave this course with a working understanding of how the system works and feel confident fully understanding drawing requirements and creating their own tolerancing schemes for parts. This course provides lots of practical hands on exercises to drive home the concepts and encourage questions and effective discussions. The exercises go beyond the theory to show how tolerancing works on real working parts.

  • Fundamentals of GD&T: Types of variation and how they’re controlled. Features of size and surfaces. Rule #1. Definitions of maximum material condition (MMC) and least material condition (LMC) and how they are used to determine bonus tolerance.
  • Tolerances of Form: Controls of flatness, straightness, circularity and cylindricity. Examples on how they are specified, their meaning and principles of verification. Straightness and flatness controls applied to features of size and surfaces.
  • Concept of Datums and the Datum Reference Frame: The common point of reference for the part definition from design through manufacturing and inspection. How imperfect parts are measured according to the design intent.
  • Tolerances of Orientation: Controls of parallelism, perpendicularity, and angularity applied to surfaces and features of size. Examples on their use and meaning as well as verification principles.
  • Tolerances of Location: Controls of position, comparison and conversion from conventional tolerancing. Applications and examples of position used for various features. Composite position tolerances. The classic examples of floating and fixed fasteners will be cited to demonstrate tolerancing for position to avoid interference problems of fit. Projected tolerance zone. Concentricity and symmetry interpretation and application.
  • Tolerances of Profile: Controls of profile of a line and profile of a surface. Equally disposed and unequally disposed profile tolerances. Profile tolerances applied to multiple surfaces. Examples of various simple and complex surfaces.
  • Tolerances of Runout: Controls of circular runout and total runout.

Learning Outcomes

  • Name the four types of variation that exist on parts, recognize the limitations of numeric tolerances and understand the need for geometric tolerances.
  • Analyze tolerances expressed numerically and calculate minimum and maximum allowable values for dimensions.
  • Understand and apply the symbols used with the geometric system of tolerances.
  • Recognize basic dimensions on prints and understand their meaning.
  • Identify and properly read feature control frames.
  • Recognize when bonus tolerance is available and calculate geometric tolerance values when bonus tolerance applies.
  • Create specifications using bonus tolerance where applicable
  • Recognize datum feature identifiers applied to features with size and surfaces.
  • Identify the datum reference frame including order of precedence.
  • Recognize when datum shift is used and calculate the amount of shift.
  • Identify and interpret geometric controls on location, orientation, form, profile & runout.
  • Construct illustrations of tolerance zones defined by geometric controls, including 3D and 2D tolerance zones,and those allowed to move.
  • Properly evaluate inspection data in light of tolerance zones defined by geometric controls.

Who Should Attend

CAD draftspersons, tool designers, technical inspectors, mechanical engineering, technicians, machine shop and tool room supervisors. Design, manufacturing, and project engineers, quality control personnel, engineering managers and supervisors will also find this workshop beneficial.

Prerequisites & Preparations

A Print Reading workshop/course is recommended as a prerequisite. The GD&T course does not review general print-reading concepts such as views, title blocks, and notes. Students who have become familiar with finding and understanding the pertinent information on prints through on-the-job experience will be prepared for this course.


About the Workshop Instructor, Charles A. Gillis, P.E. 

Charlie Gillis has over 25 years of machine design experience in industry.

Through his work with Dynamic Design Consulting, LLC, he helps clients with product design, design for assemblability and manufacturability, design documentation, tolerance stack-up analysis, and related capability-building. He has invented and designed mechanical and electro-mechanical devices of great diversity, from high-speed, fully-automated precision mechanisms and manufacturing machinery to kinetic sculptures installed as public art.

He previously served as a mechanical design engineer for The Gillette Company, designing automated machinery for manufacturing blade and razor products. He has designed equipment to manufacture the Mach3, Venus, Sensor3, Fusion, and Embrace product lines.

He has been training practicing engineers in GD&T, Print Reading, and related mechanical design and documentation topics for over 10 years.

In addition to authoring Hammer’s Blueprint Reading Basics (Industrial Press, 2017), he is also a contributing author to Machinery’s Handbook (Industrial Press, 2020), Machine Designers Reference (Industrial Press, 2011) and The Cam Design and Manufacturing Handbook (Industrial Press, 2002).

Charlie earned his Bachelor of Science Degree in Mechanical Engineering from Worcester Polytechnic Institute, and his Master of Science Degree in Mechanical Engineering from Northeastern University. He is a licensed Professional Engineer in the Commonwealth of Massachusetts, and holder of a Geometric Dimensioning and Tolerancing Professional Certificate-Senior Level (GDTP-S) from the American Society of Mechanical Engineering (ASME).