Introduction to Geometric Dimensioning & Tolerancing (GD&T) – Y14.5

Patrick J. McCuistion, PhD, GDTPS, was an Associate Professor in the Engineering Technology and Management Department at Ohio University for 25 years. He taught Engineering Graphics, Geometric Dimensioning and Tolerancing, Dimensional Analysis, Quality Management Systems, Microsoft Office Suite, and Technical Writing. Prior to that, he taught three years at Texas A&M University and one year at Pittsburg State University. He worked eight years in various engineering design, drafting, and design and drafting checking positions. He has provided instruction in geometric dimensioning, dimensional analysis, gage and fixture design, and dimensional metrology to industry, military, and educational institutions since 1986. He is certified as an ASME Geometric Dimensioning Tolerancing Professional – Senior grade and as a ADDA Mechanical Drafter.
 
Dr. McCuistion has authored one book on geometric dimensioning, three ASME University internet courses on Drawing Interpretation, Basic Geometric Dimensioning and Advanced Geometric Dimensioning, and two ASME ABC internet courses covering Drawing Formats, Line Conventions and Lettering, Orthographic and Pictorial Views, Dimensioning and Tolerancing, and Drawing Revisions.
 
Dr. McCuistion is active in the following ASME/ANSI codes and standards committees: Y14 Main, Y14.2 Line Conventions and Lettering, Y14.3 Orthographic and Pictorial Views, Y14.5 Dimensioning and Tolerancing, Y14.5.1 Mathematical Definition of Dimensioning and Tolerancing Principles, Y14.5.2 Certification of Geometric Dimensioning and Tolerancing Professionals, Y14.8 Castings, Forgings, and Molded Parts, Y14.35 Revision of Engineering Drawings and Associated Documents, Y14.36 Surface Texture Symbols, Y14.43 Dimensioning and Tolerancing Principles for Gages and Fixtures, Y14.45 Measurement Data Reporting, and Y14/B89 Joint Advisory Committee (JAC1) on the Specification of Notation to Support Requirements for Size and Geometric Tolerances.
 
Dr. McCuistion also is the Chairman of the annual SkillsUSA National Technical Drafting competition. He creates the graphics problem and written exam and serves as a judge. Competitors from all 50 states compete in one of 102 different skills-based contests in Louisville each June.

Module 1

• Introduction
  • Y14.5 2009 Dimensioning and Tolerancing standard
  • Part production
  • Design
  • Tooling / production
  • Inspection
  • Machine equipment and measuring instruments
  • GDT (Geometric Dimensioning and Tolerancing) chart

Module 2

• Datums
  • Datum brief
  • Datum features
  • Datum relationships
  • Datum combinations
  • Irregular size datum features
  • Customized datum reference frame

Module 3

• Flatness
  • Flatness Brief
  • Surface Flatness
    • Design
    • Tooling / production
    • Inspection
  • Size Feature Flatness
    • Design
    • Tooling / production
    • Inspection

Module 4

• Straightness
  • Straightness Brief
  • Line Element Straightness
    • Design
    • Tooling / production
    • Inspection
  • Size Feature Straightness
    • Design
    • Tooling / production
    • Inspection

Module 5

• Circularity/ Cylindricity
  • Circularity / Cylindricity brief
    • Design
    • Tooling / production
    • Inspection

​ Module 6

• Orientation
  • Orientation Brief
  • Line Element Orientation
    • Design
    • Tooling / production
    • Inspection
  • Surface Orientation
    • Design
    • Tooling / production
    • Inspection
  • Size Feature Orientation
    • Design
    • Tooling / production
    • Inspection

Module 7

• Runout
  • Runout Brief
    • Design
    • Tooling / production
    • Inspection

Module 8

• Profile
  • Profile Brief
    • Design
    • Tooling / production
    • Inspection
  • Conical Surfaces

Module 9

• Position Tolerance Theory
  • Position theory
  • Coordinate dimensioning
  • The 57% myth
  • Position dimensioning

Module 10

• Position: General
  • Position brief
    • Design
    • Tooling / production
    • Inspection

Module 11

• Coaxial Controls
  • Coaxial Controls
    • Design
    • Tooling / production
    • Inspection

Module 12

• Coaxial Controls
  • Noncircular Feature Control
    • Design
    • Tooling / production
    • Inspection