GD&T (Geometric Dimensioning & Tolerancing) training

Lesson 1 • Orthographic Projection Principles

Covers first- and third-angle projection, view selection, and line types. Builds the spatial reasoning required for all subsequent GD&T interpretation.

Lesson 2 • Drawing Standards and Title Blocks

Introduces ASME Y14.5 and ISO drawing standards, title block fields, and revision control. Ensures students reference the correct standard throughout training.

Lesson 3 • Basic Dimensioning Conventions

Teaches linear, angular, and radial dimensioning rules and placement best practices. Provides the baseline from which GD&T expands traditional coordinate tolerancing.

Lesson 1 • The Feature Control Frame Explained

Breaks down each compartment of the feature control frame: characteristic symbol, tolerance value, and datum references. Establishes the grammar of GD&T notation.

Lesson 2 • Geometric Characteristic Symbols Overview

Surveys all 14 geometric characteristic symbols grouped by category. Gives students a mental map before each symbol is studied in depth.

Lesson 3 • Material Condition Modifiers

Defines MMC, LMC, and RFS modifiers and their effect on tolerance zones. Connects modifier choice to functional assembly requirements.

Lesson 1 • Datum Concepts and Terminology

Defines true datum, datum feature, and datum feature simulator. Distinguishes the theoretical plane from the physical surface used in measurement.

Lesson 2 • Datum Targets and Partial Datums

Introduces datum target points, lines, and areas for irregular or non-planar surfaces. Extends datum knowledge to castings, forgings, and flexible parts.

Lesson 3 • Datum Feature Selection Strategies

Guides selection of functional, accessible, and repeatable datum features. Connects datum choice to manufacturing process and inspection setup.

Lesson 4 • Compound and Simultaneous Datums

Covers datum feature patterns, simultaneous requirements, and datum shift. Prepares students for complex multi-datum assemblies in later chapters.

Lesson 1 • Flatness Control

Defines the flatness tolerance zone as two parallel planes and explains surface vs. derived median plane application. Connects flatness to sealing and mating surface requirements.

Lesson 2 • Rule 1 and the Envelope Principle

Explains the perfect-form-at-MMC requirement and its exceptions. Establishes the boundary conditions that govern all size features before GD&T controls are added.

Lesson 3 • Circularity and Cylindricity

Defines circularity as a two-concentric-circle zone per cross-section and cylindricity as a full surface zone. Highlights their role in sealing, bearing, and press-fit applications.

Lesson 1 • Angularity Control

Covers angularity tolerance zones for surfaces and axes at specified angles to a datum. Connects angularity to inclined features in aerospace and automotive components.

Lesson 2 • Orientation Tolerance Refinement

Explains how orientation tolerances refine location tolerances and must be smaller than the location tolerance. Prevents over-constraining and conflicting callouts.

Lesson 3 • Perpendicularity Control

Defines perpendicularity tolerance zones for surfaces and axes at 90 degrees to a datum. Demonstrates its critical role in bolt-hole patterns and mating interfaces.

Lesson 1 • Bonus Tolerance Calculations

Demonstrates how MMC and LMC modifiers generate bonus tolerance as features depart from their material condition. Students perform bonus tolerance arithmetic for hole patterns.

Lesson 2 • Hole Pattern Position Controls

Applies true position to bolt-hole patterns using composite and two single-segment callouts. Distinguishes pattern location from feature-to-feature relationship control.

Lesson 3 • Concentricity and Symmetry Controls

Defines concentricity as a median-point control and symmetry as a median-plane control, both without size modifiers. Contrasts these with runout and position for functional selection.

Lesson 4 • Projected Tolerance Zone Application

Explains how projected tolerance zones control the orientation of fasteners above the part surface. Applies to threaded holes and press-fit pins in mating assemblies.

Lesson 1 • Profile Tolerance in Model-Based Definition

Introduces profile annotation in 3D CAD models using MBD standards. Bridges traditional drawing-based profile callouts to digital product definition workflows.

Lesson 2 • Profile of a Line Fundamentals

Defines the two-dimensional tolerance zone that controls cross-sectional contour shape. Connects profile of a line to extruded features and 2D cam profiles.

Lesson 3 • Bilateral, Unilateral, and Unequal Zones

Distinguishes equal bilateral zones from unilateral and unequal distribution using the U modifier. Enables precise material-side control for functional surfaces.

Lesson 4 • Composite Profile Tolerances

Applies two-tier composite profile frames to separately control location and form of complex surfaces. Mirrors composite position logic for non-cylindrical features.

Lesson 1 • Total Runout Control

Defines total runout as a full-surface FIM measurement controlling cylindricity, straightness, and coaxiality simultaneously. Identifies when total runout is required over circular runout.

Lesson 2 • GD&T Drawing Audit and Interpretation

Trains systematic review of existing drawings for errors, ambiguities, and non-conforming callouts. Builds the critical reading skills needed for design review and supplier audits.

Lesson 3 • Tolerance Analysis and Stack-Up

Applies worst-case and RSS tolerance stack-up methods to assemblies using GD&T controls. Quantifies the cumulative effect of tolerances on assembly fit and function.

Lesson 4 • Integrating GD&T on Complete Drawings

Demonstrates applying a full set of GD&T controls to a complex part drawing with proper datum structure and tolerance hierarchy. Develops the ability to author production-ready drawings.