Geometric Dimensioning and Tolerancing provides you with the complete fundamentals of geometric dimensioning and tolerancing (GD&T) concepts as published in the American Society of Mechanical Engineers (ASME) standard for engineering drawing and related documentation practices. The standard is titled ASME Y14.5-2009 Dimensioning and Tolerancing. In this text, this standard is referred to as ASME Y14.5 or ASME Y14.5-2009. Drawings based on this standard should have a general note that states: DIMENSIONING AND TOLERANCING PER ASME Y14.5-2009. The examples in this text are based on the ASME Y14.5 standard. All drawings in this text are drawn using third-angle projection. Other Y14.5 documents include ASME Y14.5.1M Mathematical Definition of Dimensioning and Tolerancing Principles and ASME Y14.5.2 Certification of Geometric Dimensioning and Tolerancing Professionals. ASME Y14.41 Digital Product Definition Data Practices is a standard that establishes requirements for applying GD&T directly to the computer-aided design (CAD) model. The standards documents that control general dimensional tolerances found in the title block and in general notes are ASME Y14.1 Drawing Sheet Size and Format for inch applications and ASME Y14.1M Metric Drawing Sheet Size and Format for metric applications. Engineering change applications are recommended by the document ASME Y14.35M Revision of Engineering Drawings and Associated Documents. Additional standards documents that relate to drafting practices include ASME Y14.3 Multiview and Sectional View Drawings, ASME Y14.100 Engineering Drawing Practices, and ASME Y14.4M Pictorial Drawing. Pictorial Drawing . Pictorial Drawing The American Society of Mechanical Engineers headquarters is located at Three Park Avenue, New York, NY 10016-5990. The ASME Web site is www.asme.org. The content of this text is considered a fundamental component to the design drafting profession by ADDA International. This publication covers topics and related material, as stated in the ADDA Curriculum Certification Standards and the ADDA Professional Certification Examination Review Guides. Although this publication is not conclusive, with respect to ADDA standards, it should be considered a key reference tool in pursuit of a professional career. For more information about the ADDA Drafter Certification Examination and becoming a certified drafter, go to www.adda.org. American Design Drafting Association (ADDA) Approved Publication 3 Introduction