ANSI B18.2.2

Square and Hex Nuts (Inch Series) ASMEIANSI B1 8.2.2-1 987 REAFFIRMED 1993 FOR CURRENT COMMITIEE PERSONNEL PLEASE SEE ASME MANUAL AS-1 1 SPONSORED AND PUBLISHED BY T H E A M E R I C A N S O C I - E T Y O F M E C H A N I C A L E N G I N E E R S United Engineering Center 345 East 47th Street New York, N. Y. 1 O0 17 Copyright ASME International Provided by IHS under license with ASME Not for ResaleNo reproduction or networking permitted without license from IHS - - ` ` - ` - ` , , ` , , ` , ` , , ` - - - Date of Issuance: August 15,1987 This Standard will be revised when the Society approves the issuance of a new edition. There will be no addenda or written interpretations of the requirements of this Standard issued to this edition. This code or standard was developed under procedures accredited as meeting the criteria for American National Standards. The Consensus Committee that approved the code or standard was balanced to assure that individuals from competent and concerned interests have had an opportunity to participate. The proposed code or standard was made available for pub!ic review and comment which provides an opportunity for additional public input from industry, academia, regulatory agencies, and the public-at-large. ASME does not "approve," "rate," or "endorse" any item, construction, proprietary device, or activity. ASME does not take any position with respect to the validity of any patent rights asserted in connection with any items mentioned in this document, and does not undertake to insure anyone utilizing a standard against liability for infringement of any applicable Letters Patent, nor assume any such liability. Users of a code or standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, is entirely their own responsibility. Participation by federal agency representativekd or personk) affiliated with industry is not to be interpreted as government or industry endorsement of this code or standard. ASME accepts responsibility for only those interpretations issued in accordance with governing ASME procedures and policies which preclude the issuance of interpretations by individual volunteers. No part of this document may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. Copyright @ 1987 by THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS All Rights Reserved Printed in U.S.A. Copyright ASME International Provided by IHS under license with ASME Not for ResaleNo reproduction or networking permitted without license from IHS --``-`-`,,`,,`,`,,`--- STD*ASME B18.2-2-ENGL L987 0759b70 Ob119707 2 1 5 m FOREWORD (This Foreword is not part of ASME/ANSI B18.2.2-1987.) American National Standards Committee B18 for the standardization of bolts, screws, nuts, rivets, and similar fasteners was organized in March 1922 as Sectional Committee BI 8 under the aegis of the American Engineering Standards Committee (later the American Standards Association, then the United States of America Standards Institute and, as of October 6,1969, the American National Standards Institute, Inc.) with the Society of Auto- motive Engineers and the American Society of Mechanical Engineers as joint sponsors. Subcommittee 2 was subsequently established and charged with the responsibility for tech- nical content of standards covering wrench head bolts and nuts. Subcommittee 2, after appraisal of the requirements of industry, developed a proposed standard series of bolt head and nut dimensions. This proposal was finally approved and designated a Tentative American Standard in February 1927. A first revision of the document was designated as an American Standard in March 1933 and was followed by a second revision which was granted approval as an American Stan- dard in January 1941. Following reorganization of the B18 Committee in 1947, Subcommittee 2 was asked to expand the standard on head proportions into a complete product standard. A proposal covering square and hexagon head bolts and nuts, hexagon head cap screws, and automo- tive hexagon head bolts was prepared and submitted to the B18 Committee in April 1950. While this draft was under consideration, the B18 Committee received a proposal from the British Standards Institution for Unification of dimensions on products incorporating uni- fied screw threads. The Committee welcomed the opportunity of discussing the proposals and an American-British-Canadian Conference was held in New York on June 1 and 2, 1950. It was agreed in the conference that the essentials of unification could be accomplished by selection of mutually satisfactory across-the-flats dimensions, since this would permit the use of the same wrenches and because other features would rarely affect interchangeability. After due consideration, suitable existing across-the-flats dimensions were selected for the hexagon products affected. In its meeting of October 13,1950, Subcommittee 2 agreed to incorporate in the proposed standard the conference recommendations on y4 in. hexagon head bolts, 78 in. hexagon head cap screws and automotive hexagon head bolts, YI6 in. and y8 in. regular hexagon and square nuts, and 1/16 in. light and regular hexagon and square nuts. At a subsequent meeting of Subcommittee 2, further changes were adopted in order to combine the light and regular series of nuts, and to combine the automotive hexagon head bolt, hexagon head cap screw, and regular hexagon head close tolerance bolt. In view of the prógress made in the United States and the urgency of standardization for mutual defense, the British Standards Institution sponsored a second Conference in Lon- don in April 1951 to complete the unification of certain hexagon bolts and nuts. At a meeting on June 8, 1951, Subcommittee 2 reaffirmed its acceptance of the unified di- mensions which correspond with those in the March 1951 draft, but attempted to select bet- ter nomenclature for the unified products. A final draft incorporating the nomenclature iii Copyright ASME International Provided by IHS under license with ASME Not for ResaleNo reproduction or networking permitted without license from IHS - - ` ` - ` - ` , , ` , , ` , ` , , ` - - - “Finished Hexagon Bolts and Nuts” and containing numerous editorial changes was sub- mitted for letter ballot in September 1951. Following approval by the B18 committee and the sponsors, the proposal was presented to the American Standards Association for ap- proval and designation as an American Standard. This was granted on March 24, 1952. It being recognized that the standard was in need of additional refinements, Subcommit- tee 2 began work immediately to eliminate these shortcomings. A proposed revision remov- ing inconsistencies with respect to fillets, improving the length tolerances on heavy hexagon bolts, and incorporating numerous other corrections and clarifications of an editorial nat- ure, resulted. The most noteworthy editorial change was a decision to combine the coverage for hexagon cap screws and square head set screws from the B18.2 standard with the cover- age for slotted head cap screws and slotted headless set screws from the B18.6 standard for publication in a separate document. The requirements for the unified hexagon cap screws and finished hexagon bolts being identical in the overlapping sizes, the data would now be available in two publications. Following approvals by the B18 Committee and sponsor or- ganizations, the proposal was submitted to the American Standards Association and de- clared an American Standard on February 2, 1955. A revision of this document comprised of numerous editorial corrections and inclusion of an appendix for grade markings was duly approved and designated an American Stan- dard on April 18, 1960. At a meeting in February 1960, Subcommittee 2 approved a recommendation to reduce the head heights for heavy, heavy semi-finished, and heavy finished hexagon bolts which was subsequently approved by letter ballot of the B18 Committee on August 16, 1960. A proposed standard for heavy hexagon structural bolts submitted and accepted by Subcom- mittee 2 at its October 17, 1960 meeting was approved by letter ballot of the B18 Committee on May 9, 1961, To meet the urgent needs of the steel construction industry it was consid- ered necessary to publish the standard for the structural bolts immediately. Consequently, Appendix IV to ASA B18.2-1960 containing coverage for the revised heavy hexagon bolts and the new heavy hexagon structural bolts was released in 1962. In October of. 1961, Subcommittee 2 appointed a subgroup to review all product stan- dards for square and hexagon bolts, screws, and nuts, and to recommend simplifications which would be compatible with technical, production, and distribution advances that had occurred over the prior several years. The subgroup presented its recommendations at a meeting of Subcommittee 2 in October of 1962. It being agreed that the internally and exter- nally threaded products should be published in separate documents as suggested, draft pro- posals for each were completed. The proposed revision for square and hex nuts incorporated the following subgroup rec- ommendations: discontinuation of regular semi-finished nuts; elimination of regular hexa- gon and heavy hexagon nuts in sizes !4 in. through 1 in.; elimination of finished hexagon nuts in sizes larger than 1 ‘/z in.; elimination of the washer face semi-finished style on fin- ished series nuts in sizes % in. and smaller and heavy series nuts in sizes 7/16 in. and smaller; removal of machine screw nuts (these nuts now contained in B18.6.3); and adoption of an abbreviated product nomenclature. Letter ballot of this proposal to the B18 Committee re- sulted in approval. Following acceptance by the sponsor organizations the revision was sub- mitted to the American Standards Association and designated ASA B1 8.2.2 on September 8, 1965. Subcommittee 2 continued to further develop refinements initiated by the simplification subgroup and study changes suggested by consumer interests. This work culminated in Sub- committee acceptance of a 1970 proposal incorporating, in addition to numerous editorial changes, revisions to the requirements on angularity of bearing face and countersink diame- ters for the various hex nuts and heavy hex nuts, and inclusion of an appendix covering the gaging of slots in slotted nuts. The proposed revision, after approval by letter ballot of the B18 Committee in March 1970, was subsequently approved by the sponsors and submitted iv Copyright ASME International Provided by IHS under license with ASME Not for ResaleNo reproduction or networking permitted without license from IHS - - ` ` - ` - ` , , ` , , ` , ` , , ` - - - to the American National Standards Institute for designation as an American National Standard. This was granted on January 18, 1972. A proposed revision of the standard agreed upon by Subcommittee 2 incorporated a pro- vision to enable consumers to specify heavy hex nuts and heavy hex jam nuts with close bearing face angularity, when required; clarified intent with regard to width across flats on nuts produced from bar stock; deleted coverage for hex castle nuts from the appendices; and included numerous editorial refinements. This proposal was formally approved by let- ter ballot of the subcommittee and the B18 Committee. Following its acceptance by the sponsor organizations the revision was referred to the American National Standards Insti- tute and granted recognition as an American National Standard on February 27, 1987. V Copyright ASME International Provided by IHS under license with ASME Not for ResaleNo reproduction or networking permitted without license from IHS - - ` ` - ` - ` , , ` , , ` , ` , , ` - - - ASME STANDARDS COMMITTEE B18 Standardization of Bolts, Nuts, Rivets, Screws, Washers, and Similar Fasteners (The following is the roster of the Committee at the time of approval of this Standard.) OFFICERS J. B. Levy, Chairman H. W. Ellison, Vice Chairman E. Schwartz, Vice Chairman R. W. McGinnis, Secretary COMMITTEE PERSONNEL AMERICAN SOCIETY OF AGRICULTURAL ENGINEERS E. R. Friesth, Don E. Williams Co., Rock Island. Illinois AMERICAN SOCIETY OF MECHANICAL ENGINEERS A. R. Machell, Webster, New York K. E. McCullough, SPS Technologies Inc., Jenkintown, Pennsylvania ENGINE MANUFACTURERS ASSOCIATION G. A. Russ, Cummins Engine Co., Columbus, Indiana FARM & INDUSTRIAL EQUIPMENT INSTITUTE D. A. Clever, Deere & Co., Moline, Illinois HAND TOOL INSTITUTE R. B. Wright, Wright Tool Co., Barberton, Ohio INDUSTRIAL FASTENERS INSTITUTE D. J. Broomfield, Illinois Tool Works Inc., Elgin, Illinois O. A. Garrison, Russell, Burdsall & Ward Corp., Rock Falls, Illinois R. M. Harris, Bethlehem Steel Corp., Lebanon, Pennsylvania D. Lidl. Greensburg, Pennsylvania J. C. McMurray, Alternate, Russell, Burdsall & Ward Inc., Cleveland, Ohio J. S. Orlando, Chicago, Illinois E. Sterling, Emhart Corp., Campbellsville, Kentucky J. A. Trilling, Holo-Krome Co., West Hartford, Connecticut S. W. Vas. Lake Erie Screw Corp., Cleveland, Ohio C. J. WJson, Industrial Fasteners Institute, Cleveland, Ohio METAL CUTTING TOOL INSTITUTE D. Emanuelli, TRW - Greenfield Tap & Die, Greenfield, Massachusetts NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION J. B. Levy, Scotia, New York W, F. Montavon, Alternate, National Electrical Manufacturers Association, Washington, D.C. F. F. Weingruber, Westinghouse Electric Corp., Pittsburgh, Pennsylvania NATIONAL FASTENERS DISTRIBUTORS ASSOCIATION J. F. Sullivan, Accurate Fasteners, Inc., South Boston, Massachusetts vii Copyright ASME International Provided by IHS under license with ASME Not for ResaleNo reproduction or networking permitted without license from IHS --``-`-`,,`,,`,`,,`--- SOCIETY OF AUTOMOTIVE ENGINEERS H. W. Ellison, General Motors Corp., Warren, Michigan R. S. Piotrowski, Mack Trucks Inc., Allentown, Pennsylvania TUBULAR & MACHINE INSTITUTE R. M. Byme. Trade Association Management Inc., Tarrytown, New York J. G. Zeratsky, National Rivet & Manufacturing Co., Waupun, Wisconsin U. S. DEPARTMENT OF THE ARMY M. E. Taylor, U. S. Army Armament, Munitions & Chemical Command, Dover, New Jersey A. Herskovitz, Alternate, U. S. Army Armament, Munitions & Chemical Command, Dover, New Jersey J. E. Long, Alternate, U. S. Army Tank Command, Warren, Michigan U. S. DEPARTMENT OF DEFENSE E. Schwartz, Defense Industrial Supply Center, Philadelphia, Pennsylvania L. Pieninck, Alternate, Defense Industrial Supply Center, Philadelphia, Pennsylvania U. S. DEPARTMENT OF THE NAVY J. E. Hass, Department of the Navy, Washington, D.C. M. S. Orysh, Alternate, Department of the Navy, Philadelphia, Pennsylvania INDIVIDUAL MEMBERS A. R. Breed, Lakewood, Ohio R. A. Flor, Chrysler Corp., Detroit, Michigan G. A. Gobb, Ford Motor Co., Dearborn, Michigan F. E. Graves, F. E. Graves Assoc., Fairfield, Connecticut J. J. Naesset. Clark Equipment Co., Battle Creek, Michigan SUBCOMMITTEE 2 - SQUARE AND HEX BOLTS AND NUTS S. C. Adamek, Pheoll Mfg. Co., Chicago, Illinois A. R. Breed, Lakewood, Ohio R. M. Byme. Tarrytown, New York D. A. Clever, Deere & Co., Moline, Illinois W. J. Demer, FMC Corp., Indianapolis, Indiana D. A. Garrison, Russell, Burdsall &Ward Corp., Rock Falls, Illinois F. E. Graves, Fairfield, Connecticut R. M. Hams, Bethlehem Steel Corp., Lebanon, Pennsylvania J. B. Levy, Scotia, New York A. R. Machell, Webster, New York K. E. McCullough, SPS Technologies, Jenkintown. Pennsylvania J. C. McMurray, Russell, Burdsall &Ward Corp., Cleveland, Ohio A. Nebesny, Alternate, FMC Corp., Indianapolis, Indiana I. M. Park, Stelco Wire Products, Ontario, Canada L. Pieninck, Alternate, Defense Industrial Supply Center, Philadelphia, Pennsylvania R. L. Tennis, Caterpillar Tractor Co., Peoria, Illinois S. W. Vass. Lake Erie Screw Corp., Cleveland, Ohio F. F. Weingruber, Westinghouse Electric Corp., Pittsburgh, Pennsylvania C. J. Wilson, Industrial Fasteners Institute, Cleveland, Ohio viii Copyright ASME International Provided by IHS under license with ASME Not for ResaleNo reproduction or networking permitted without license from IHS - - ` ` - ` - ` , , ` , , ` , ` , , ` - - - CONTENTS ... Foreword .............................................................. 111 Standards Committee Roster .............................................. vii 1 Introductory Notes .................................................. 1 2 General Data ....................................................... 1 Tables 1 Dimensions of Square Nuts ........................................... 3 2 Dimensions of Hex Flat Nuts and Hex Flat Jam Nuts .................... 5 3 Dimensions of Hex Nuts and Hex Jam Nuts ............................ 7 4 Dimensions of Hex Slotted Nuts ...................................... 9 5 Dimensions of Hex Thick Nuts ....................................... 11 6 Dimensions of Hex Thick Slotted Nuts ................................. 13 7 Dimensions of Heavy Square Nuts .................................... 15 8 Dimensions of Heavy Hex Flat Nuts and Heavy Hex Flat Jam Nuts ........ 17 10 Dimensions of Heavy Hex Slotted Nuts ................................ 24 9 Dimensions of Heavy Hex Nuts and Heavy Hex Jam Nuts ................ 20 Appendices I Slot Gages and Gaging for Slotted Nuts ................................ 27 II Formulas for Nut Dimensions ........................................ 29 III Wrench Openings Applicable to Square and Hex Nuts ................... 33 ix