One Day Work Shop Presented By CTRI (CT Research Institute)

Research and Training wing of Western Thomson Group


GD & T is a means of dimensioning & tolerancing a drawing which considers the shape and function of the part and how this part functions with related parts. This allows a drawing to contain a more defined feature more accurately.

Since many major industries are becoming more global, resulting in the decentralization of design and manufacturing, it is even more important that the design, more precisely state the functional requirements.

After attending this workshop the participant will have a clear understanding on the application of GD&T concepts in design and manufacture.


Basic Concepts and Form Tolerances
  • Introduction to GD & T – Importance - Terminology - General rules - Symbols - Datum references Form tolerances – Flatness, Straightness, Circularity, Cylindricity - Measurement.
Orientation and Profile tolerance
  • Tolerances of Orientation – Parallelism, Perpendicularity, Angularity, orientation tolerance zone, measurement methods.
  • Profile Tolerances – Types, Surface and line - Tolerance zone boundaries, Applications of profile tolerance, Measurement methods.
Positional Tolerances
  • Tolerances of Location – Position, Concentricity, Symmetry, Modifier symbols – MMC,LMC, RFS – Bonus Tolerances – Examples, Exercise - Application and measurement.
  • Tolerances of Runout - Circular runout, Total runout – Measurement of runout
Application of GD & T
  • Interpretation of real time drawings with GD & T and exercises
Application of GD & T in design
  • Determining GD&T requirements based on application - Design Exercise