Interpretation of Geometric Dimensioning and Tolerancing

Dan Puncochar was most recently manager of Corporate Quality Assurance for the world’s largest truck manufacturer. His career spanned 30 years. Previously, he held positions in the Engineering Test Lab and in the Corporate Training Department, where he instructed production workers in basic and advanced courses in machine technology. He also taught quality assurance inspectors blueprint reading and GD&T – among other courses — and subsequently was called on to teach GD&T throughout the Corporation.

Ken Evans is a machine tool Sales Engineer for a leading distributor of metal cutting and quality control equipment and services. Previously, he was a Machine Tool Technology instructor at Davis Applied Technology College (Utah), where he taught for nearly 20 years. Ken started in the machining trade at Cessna Aircraft in 1976. He has since held a wide variety of machining and related jobs throughout his career: Machine Tool Technology Instructor, Prototype CNC Machinist, Quality Control Inspector, Mold Maker, Tool & Die Maker. He is the author of Programming of CNC Machines, 3^rd Edition, and the accompanying Student Workbook, both available from Industrial Press.

Contents

• Introduction
• Symbols and Abbreviations
• Datums
• Feature Control Frames
• General Rules
• Form and Orientation Tolerances
• Virtual Condition
• Tolerances of Location
• Practical Application Appendices: Past, Plus/Minus Positional Tolerancing, Symbols
• Glossary
• “Dimensioning and the Tolerancing” Standard