ANSI is the abbreviation for American National Standards Institute. ANSI is a private, non-profit organization whose charter is to coordinate the development of voluntary consensus standards. Also, ANSI is the United States representative to ISO, an international organization also involved in the creation of standards. ANSI´s mission is:


ANSI Mission To enhance both the global competitiveness of U.S. business and the U.S. quality of life by promoting and facilitating voluntary consensus standards and conformity assessment systems, and safeguarding their integrity. (From


The members of ANSI are companies, government agencies, universities and individuals interested in the creation, use, and maintenance of standards and on the certification of products and personnel to the standards. ANSI coordinates but not produce the standards. The standards are produced by the member companies, organizations and individuals that have an interest in the subject. Typically, a draft of the standard produced by a member is circulated to others for changes and eventual approval by consensus.


ANSI was created in 1919 as the American Engineering Standards Committee (AESC). Its Headquarters are in Washington, DC but its operations are based in the New York City. From the beginning ANSI has been the voice of standardization for most of the engineering societies including ASCE, ASME, IEEE, ASTM and AIME. The United States’ military has transferred many of its standards to ANSI, including the Drafting Standard.


Technical drawings that follow the ANSI standard are drawn in inches or millimeters and are projected in the third quadrant or angle. They should have the symbol in Figure A.1 below to indicate the third angle projection. Figure A.2 is a representation of the third angle projection and Figure A.3 shows how the third angle projection looks in a technical drawing.