ASME_B18.2.3.2-2005.pdf

ASME B18.2.3.2M-2005Revision of ASME B18.2.3.2M-1979(R1995)Metric FormedHex ScrewsAN AMERICAN NATIONAL STANDARDThe American Society ofMechanical EngineersonmASME B18.2.3.2M-2005Revision of ASME B18.2.3.2M-1979(R1995)Metric FormedHex ScrewsAN AMERICAN NATIONAL STANDARDThe American Society ofMechanical EngineersThree Park Avenue.New York,NY 10016Notfor ResaleCONTENTS444444Committee RosterVCorrespondence With the B18 Committeev.2comparison With ISO Standards.34Referenced Standards.5Dimensions.6General Data2Figures2Formed Hex Screws.22Eillet Details For Short Screws.33Fillet Details For Long Screws.A1Typical Straightness Gage.9B1Typical Gage.10Tables1Dimensions of Formed Hex Screws.23Dimensions of Underhead Fillets.44Dimensions of Reduced Body Diameter With Shoulder.45Maximum Grip Gaging Lengths and Minimum Body Lengths.5.6Length7DimensionS Of POints.68Thread Length6Nonmandatory AppendicesAScrew Straightness Gage and Gaging Procedure.9BBody Position Gages and Gaging Procedures.10Comparison With ISO Standards.11ermitted without Scense from IHSNot for ResaleFOREWORDAmerican National Standards Committee B18 for the standardization of bolts,screws,nuts,riv-ets,and similar fasteners was organized in March 1922 as Sectional Committee B18 under theaegis of the American Engineering Standards Committee(later the American Standards Associ-ation,then the United States of America Standards Institute and,as of October 6,1969,the Amer-ican National Standards Institute,Inc.),with the Society of Automotive Engineers and the Amer-ican Society of Mechanical Engineers as joint sponsors.Subcommittee 2 was subsequentlyestablished and charged with the responsibility for technical content of standards covering wrenchhead bolts and nuts.At its meeting on December 4,1974,Committee B18 authorized preparation of a series of stan-dards for metric fasteners.Subcommittee 2 was assigned responsibility for developing standardsfor metric hex bolts,screws,and nuts.At a meeting on September 22,1976,Subcommittee 2 organized the contents of a standard cov-ering eight different hex head screw and bolt products.Actual drafting was postponed untilISO/TC2 could reach final decisions relating to basic dimensions and characteristics of hex bolts,screws,and nuts.At ISO/TC2 meetings held in April 1977,final actions were taken.CommitteeB18 affirmed the TC2 decisions at a meeting on June 29,1977 and drafting of this Standard wasstarted.In February 1978,Committee B18 established a cooperative program with the Department ofDefense to draft American National Standards for metric fasteners in such a way that they couldbe used directly by the Government for procurement purposes.The Department of Defense re-quested that each of the eight products be covered in separate standards,and Subcommittee 2accepted this approach at its meeting on June 27,1978.The previous edition of this Standard was approved by letter ballot of Committee B18 on De-cember 15,1978,and was subsequently approved by the secretariat and submitted to the Amer-ican National Standards Institute for designation as an American National Standard.This wasgranted on March 29,1979.B18.2.3.2M was last reaffirmed without change in 1995.This Standard was developed by the American Society of Mechanical Engineers B18 StandardsCommittee on Fasteners.This Standard was approved by the American National Standards In-stitute on April 29,2005.ivNot for Resale