The Ultimate GD&T Crash Course- GD and T from zero to hero

Master Geometric Dimensioning and Tolerancing GD&T from scratch – a Comprehensive Approach. Course creation IN PROGRESS

Please note: Course IN PROGRESS , New lectures are added weekly

What you’ll learn

  • Why GD&T and a brief history , role of mechanical design and tolerances in the product development process.
  • Advantages of Geometric Dimensioning and Tolerancing over the +/- system.
  • Form Tolerances: Straightness of a centerline and of a line, Flatness, Circularity & cylindricity, Profile of a line and of a surface.
  • Datums, datum targets and datum systems.
  • Parallelism, Perpendicularity and Angularity.
  • Concentricity, Coaxiality, and Position tolerance.
  • axial and radial run-out tolerances.
  • Specification modifiers: LP GN GX and Complementary specification modifiers: ACS SCS ALS , indicators.
  • Tolerance zone modifiers: Combined zone CZ , separate zone SZ, Unidirectional Tol. Zone UZ.
  • Material Condition Modifiers: Maximum material condition, Least material condition.

Course Content

  • Introduction –> 3 lectures • 22min.
  • Form Tolerances –> 6 lectures • 38min.
  • Orientation Tolerances –> 3 lectures • 18min.

The Ultimate GD&T Crash Course- GD and T from zero to hero


Please note: Course IN PROGRESS , New lectures are added weekly

welcome you to the GD&T crash course developed by design engineers with years of experience in the automotive industry.

The course for anyone who wants to understand Geometric Dimensioning and Tolerancing in a simple and intuitive way. This course is ideal for an engineering student preparing for a mechanical engineering degree , Or for an an engineer or technician who sometimes work with technical drawings and wants to master how to read them


We will cover topics such as:

  • Introduction and advantages of GD&T over the + – tolerance system
  • From Tolerances
    • Straightness
    • Flatness
    • Circularity
    • Cylindricity
    • Line profile
    • Surface profile
  • Orientation Tolerances
    • Parallelism
    • perpendicularity
    • Inclination (Angularity)
    • Line profile
    • Surface profile
  • Location Tolerances
    • Position
    • Concentricity
    • Coaxiality
    • Line profile
    • Surface profile
  • Run-out Tolerances
    • Run-out
    • Total run-out
  • Datums
    • Datums , Datum Targets
    • Datum Systems


  • Modifiers
    • Specification modifiers
    • complementary specification modifiers
    • Tolerance zone modifiers
    • Toleranced geometrical element modifiers
    • Material Condition Modifiers: Maximum Material Condition MMC and Least Material Condition LMC


  • Course Project in the course project you will apply the gained knowledge in the course to add GD&T tolerances to a Piston crank shaft assembly based on the function of each feature of each part!

As well as explaining from scratch what these symbols mean, we will go through the most common mistakes so you can avoid them. You will understand the concepts and test the knowledge with quizzes and assignments.


GD& T is the language of design engineers, come and join us and speak it fluently