Geometric Dimensioning and Tolerancing Course

Lesson 1 • Dimensioning Fundamentals

Teaches linear, angular, and radial dimensioning rules and placement logic. Provides the baseline from which GD&T tolerances extend and refine size control.

Lesson 2 • Limits, Fits, and Tolerances Overview

Explains plus/minus tolerancing, limit dimensions, and fit classifications. Contextualises why GD&T replaces or supplements coordinate tolerancing for complex parts.

Lesson 3 • Drawing Standards and Title Blocks

Introduces international and industry drawing standards, title block fields, and revision control. Ensures students can locate and verify critical drawing metadata.

Lesson 1 • Modifiers and Material Condition Concepts

Introduces MMC, LMC, RFS, and free-state modifiers and their placement rules. Students predict how modifiers shift tolerance zone size and inspection strategy.

Lesson 2 • The Feature Control Frame Anatomy

Decodes each compartment of the feature control frame: characteristic symbol, tolerance value, and datum references. Provides the grammar for all GD&T specifications.

Lesson 3 • Geometric Characteristic Symbols

Surveys all fourteen GD&T characteristic symbols grouped by category. Students associate each symbol with its controlled geometric behaviour.

Lesson 4 • Reading Complete GD&T Callouts

Integrates symbol, modifier, and datum knowledge to interpret full drawing callouts. Students parse complex multi-segment and composite callouts without ambiguity.

Lesson 1 • Compound and Simultaneous Datum Requirements

Addresses compound datum features, simultaneous requirements, and separate requirement callouts. Students resolve complex multi-feature datum schemes on production drawings.

Lesson 2 • Degrees of Freedom and Constraint

Applies six-degrees-of-freedom analysis to datum reference frame construction. Students determine which DOF each datum constrains and verify complete part location.

Lesson 3 • Datum Precedence and Order

Explains primary, secondary, and tertiary datum hierarchy and its effect on part orientation. Students sequence datums to minimise measurement uncertainty.

Lesson 4 • Datum Targets and Irregular Surfaces

Covers datum target points, lines, and areas for castings, forgings, and flexible parts. Students specify datum targets that simulate functional tooling contact.

Lesson 1 • Circularity and Cylindricity Controls

Explains circularity as a cross-sectional control and cylindricity as a full-surface control. Students select the appropriate control based on functional sealing or bearing requirements.

Lesson 2 • Angularity, Perpendicularity, and Parallelism

Covers the three orientation controls, their datum requirements, and tolerance zone orientations. Students apply orientation callouts to surfaces, axes, and centre planes.

Lesson 3 • Flatness and Straightness Controls

Defines flatness and straightness tolerance zones and their datum-independent nature. Students distinguish surface flatness from derived median plane straightness.

Lesson 1 • Profile Tolerance Fundamentals

Defines profile tolerance zones as uniform offsets from true profile geometry. Students understand how profile simultaneously controls size, form, orientation, and location.

Lesson 2 • Profile of a Line vs. Surface

Contrasts cross-sectional line profile with full three-dimensional surface profile control. Students select the correct profile type based on manufacturing and inspection capability.

Lesson 3 • Profile on Complex and Freeform Surfaces

Applies profile tolerancing to sculptured surfaces, blends, and non-uniform tolerance zones. Students write and interpret dynamic profile and non-uniform profile callouts.

Lesson 4 • Profile Tolerance Verification Methods

Covers CMM scanning, optical scanning, and functional gauging for profile verification. Students select appropriate measurement strategies for different surface complexity levels.

Lesson 1 • Bonus Tolerance and MMC Application

Explains how MMC modifier generates bonus tolerance as features depart from maximum material condition. Students compute total allowable position tolerance for given feature sizes.

Lesson 2 • Functional Gauging for Position

Designs fixed and adjustable functional gauges for positional verification at MMC. Students calculate gauge pin sizes and datum simulator dimensions from drawing callouts.

Lesson 3 • Concentricity, Symmetry, and Coaxiality

Defines concentricity and symmetry as median-point controls and contrasts them with runout and position. Students select the correct coaxiality control for functional requirements.

Lesson 4 • True Position Fundamentals

Defines true position as the theoretically exact location of a feature relative to datums. Students calculate positional tolerance zones from basic dimensions and datum references.

Lesson 1 • Circular Runout Fundamentals

Defines circular runout as a composite cross-sectional control of coaxiality and form. Students apply circular runout to rotating shafts, flanges, and tapered surfaces.

Lesson 2 • Surface Texture Symbols and Parameters

Introduces Ra, Rz, and waviness parameters and the surface texture symbol structure. Students specify surface finish requirements that align with functional contact and sealing needs.

Lesson 3 • Datum Setup for Runout Measurement

Covers datum axis establishment using V-blocks, centres, and precision chucks for runout inspection. Students identify datum feature quality requirements that affect runout measurement validity.

Lesson 1 • Common GD&T Errors and Corrections

Catalogues frequent specification errors, ambiguous callouts, and over-toleranced features found in industry. Students diagnose and correct flawed drawings using standard interpretation rules.

Lesson 2 • General Rules and Fundamental Concepts

Reviews Rule 1, Rule 2, and the independency principle as the governing framework for all GD&T. Students apply these rules to resolve ambiguities on production drawings.

Lesson 3 • Tolerance Stack-Up Analysis

Applies worst-case and statistical stack-up methods to assemblies with multiple GD&T callouts. Students identify critical tolerance chains and optimise individual tolerances for assembly yield.

Lesson 4 • Applying GD&T in Design Practice

Challenges students to tolerance complete part drawings from functional requirements using all learned controls. Students justify each callout choice with a functional rationale.