1、25 February 1987 SUPERSEDING 21 June 1982 ANSI/ACME B18 -3.1EI-1986 ACCEPTANCE NOTICE This non-Government document was adopted on 25 February 1987, and is The indicated industry group has furnished approved for use by the DoD. the clearance required by existing regulations. Copies of the document ar
2、e stocked by the DoD Single Stock Point, Naval Publications and Forms Center, Philadelphia, PA 19120-5099, for issue to DoD activities only. Contractors and Industry groups must obtain copies directly from: The American Society of Mechanical Ingineers United Engineering Center, 345 E. 47th Street, N
3、ew York, NY 10017 or The American National Standards Institute, 1430 Broadway, New York, NY 10018. Title of Document: Screw, Cap, Socket Head-Metric Series Document Number : ASME/ANSI B18.3.1M-1986 Date of Specific Issue Adopted: 29 August 1986 Releasing Industry Group: The American Society of Mecha
4、nical Engineers NOTICE: When reaffirmation, amendment, revision, or cancellation of this standard is initially proposed, the industry group responsible for this standard shall inform the military coordinating activity of the proposed change and request participation. Cu s t od ians : Army - AR Navy
5、- AS Air Force - 99 Military Coordinating Activity: Army - AR (Project 5305-1672) Review Activities: Army - AT, AV, CR, EA, MI NSA - NS DLA - IS User Activities: Army - ME Navy - MC, OS, SH Civil Agency Coordinating Activities: (;SA - FSS AM!X N/A 1-1 Copyright ASME International Provided by IHS und
6、er license with ASMENot for ResaleNo reproduction or networking permitted without license from IHS-,- s.: . - AN AMERICAN NATIONAL STANDARD t f Socket Head Cap Screws (Metric Series) 4 ASMEIANSI BI 8.3.1 M-1986 I i %- (REVISION OF ANSVASME BI 8.3.1 M-1982) Government Key Words: Screw, Cap, Socket He
7、ad - Metric SPONSORED AND PUBLISHED BY THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS United Engineering Center 345 East 47th Street New York, N. Y. 1 O01 7 # % ,- o Copyright ASME International Provided by IHS under license with ASMENot for ResaleNo reproduction or networking permitted without licens
8、e from IHS-,-,ASME BL8.3-lM 86 a 075.7b70 0043411 L Date of Issuance: February 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
9、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 tq participate. The propose
10、d code or standard was made available for public 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.
11、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 li
12、ability. 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 representativeis) or person(si affiliated with industry is not t
13、o 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 docume
14、nt may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. Copyright 0 1987 by THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS All Rights Reserved Printed in U.S.A. Copyright ASME International Provided by IHS under license w
15、ith ASMENot for ResaleNo reproduction or networking permitted without license from IHS-,-ASME B18-3.1M 86 m 0759670 0043412 3 m FOREWORD (This Foreword is not part of ASME/ANSI B18 lh 1986.) American National Standards Committee B18 for the standardization of bolts, screws, nuts, rivets, and similar
16、 fasteners was organized in March 1922 as Sectional Committee B18 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) wi
17、th the Society of Automo- tive Engineers and the American Society of Mechanical Engineers as joint sponsors. Subcommittee No. 9 was established in April 1929 to undertake development and oversee maintenance of standards covering socket head cap screws and set screws. In line with a gen- eral realign
18、ment of the Subcommittee structure on April 1 , 1966, Subcommittee 9 was re- designated Subcommittee 3. Over the intervening years this activity has produced several versions of American National Standards covering inch series socket cap, shoulder, and set screws bearing the B18.3 designation. At th
19、e December 4, 1974 meeting of American National Standards Committee B18, Sub- committee 3 was assigned the task of preparing standards for metric series socket screw products paralleling that contained in the latest ANSI B18.3 document. The Subcommittee was also instructed to continue coordinating t
20、hat activity with the International Standards Organization, IS0 Technical Committee 2, and Working Group 3, and to the extent possi- ble, keep the proposals for metric standards under development in conformance with agree- ments reached therein. At the February 19,1975 meeting of Subcommittee 3, it
21、was agreed that the following ba- sic principles be considered in developing the metric version of the standard. (a) To assure consumers continuity of performance integrity consistent with inch socket screw products, the metric standards should maintain the same quality levels as their inch counterp
22、arts. (b) To facilitate and expedite the processing, acceptance, and adoption of the metric ver- sions, proposals for the various product categories should be prepared as separate and com- plete product standards. (c) To promote understanding and assimilation during the transition to metric, the di-
23、 mensional symbols, designations, terminology, and basic formats of the metric standards should be kept similar to those used in the ANSI B18.3 document. In line with the foregoing, it was also agreed that a proposal covering metric series socket head cap screws based on the socket screw industry do
24、cument, recognizing only alloy steel screws conforming to IS0 property class 12.9 and containing data paralleling that under de- velopment by ISO/TC2/WG3 for updating the IS0 R861 standard, be circulated for Sub- committee consideration. It was noted that due to diverse methods of tolerancing, sever
25、al noncritical dimensions such as head diameter, head height, key engagement, and wall thick- ness reflected minor differences from the IS0 values at their extremes. Consequently, a draft standard documenting these dimensional differences in an appendix and denoting that screws would be considered b
26、oth functional and acceptable to these dimensions during the transition period was prepared and adopted by Subcommittee 3. Letter ballot of the ini- tial proposal to Committee B18 resulted in extensive comments. A redraft incorporating iii Copyright ASME International Provided by IHS under license w
27、ith ASMENot for ResaleNo reproduction or networking permitted without license from IHS-,-resolutions of these comments, changes appearing in IS0 4762-1977, plus contemplated re- visions thereto, and addition of government procurement data, was accepted by the B18 Committee in September 1977. After a
28、pproval by the sponsor organizations, the proposed standard was submitted to the American National Standards Institute and granted recogni- tion as an American National Standard on April 5, 1978. Updating of the standard was initiated at the May 1979 meeting of Subcommittee 3, and discussions held o
29、ver two ensuing meetings resulted in agreement that the document should be revised to incorporate changes to the tolerance on length, the grip, body lengths, and thread documentation; add dimensions for drilled head screws as an appendix; and elimi- nate the extensive data pertaining to nondimension
30、al and performance requirements in fa- vor of referencing the ASTM A 574M specification which had been released in the interim. A proposal embodying these changes along with extensive editorial refinements was pre- pared. Subsequent to Subcommittee acceptance, the proposal was approved by letter bal
31、lot to American National Standards Committee B18 and duly submitted for approval by the sponsor organizations and the American National Standards Institute. The revision was of- ficially designated an American National Standard on February 18, 1982. A periodic review of the standard, undertaken by t
32、he Subcommittee in 1985, resulted in agreement that the standard be revised to reflect interchangeability with screws made to IS0 documents and to incorporate by reference the new ASTM documents for the appropriate mechanical, chemical, and testing requirements of metric socket head cap screws. A pr
33、o- posal containing these changes, as well as editorial corrections, was prepared for and bal- loted by letter ballot to ASME Committee B18. Following approval by ASME, the proposal was submitted to the American National Standards Institute and designated an American National Standard on August 29,
34、1986. iv ,- ! Copyright ASME International Provided by IHS under license with ASMENot for ResaleNo reproduction or networking permitted without license from IHS-,-i - ASME STANDARDS COMMITTEE BI8 Standardization of Bolts, Nuts, Rivets, Screws, Washers, and Similar Fasteners (The following is the ros
35、ter 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 AME
36、RICAN 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 (b) Nominal size of screw; (c) Thread pitch, preceded by x ; (d) Nominal sc
37、rew length, preceded by X ; (e) Product name. If desired, the product name may be abbreviated SHCS. u Material and property class. Alloy steel screws shall be supplied to property class 12.9 as specified in ASTM A 574M. For corrosion-resistant steel screws, the property class and material requiremen
38、ts shall be as specified in ASTM F 837M (see para. 3.1). (g) Drive. Unless specified otherwise, the socket shall be hexagon. 1 Copyright ASME International Provided by IHS under license with ASMENot for ResaleNo reproduction or networking permitted without license from IHS-,-ASME Bl18-33M 86 1375967
39、0 0043438 9 ASMEIANSI B18.3.1M-1986 (h) Protective finish, if required (see para. 3.3). Examples: B18.3.1M I -6 x 1 x 20 I Hexagon Socket Head Cap Screw, Alloy Steel ProductName +:ber z?f-y or Abbreviation B18.3.1M - 10 x 1.5 x 40 SHCS, Alloy Steel Zinc Plated B18.3.1M - 8 x 1.25 x 30 Spline SHCS Al
40、-70. 1.8 Part Numbering System tem, one is suggested in Appendix V. For users who need a definitive part numbering sys- 2 DIMENSIONAL CHARACTERISTICS The following requirements supplement the dimen- sional data presented in Tables 1, 2, and 3 and shall apply to the respective features of screws. 2.1
41、 Heads 2.1 .I Head Diameter. Heads may be plain or knurled at the option of the manufacturer unless spec- ified otherwise by the customer. For knurled screws the maximum head diameter shall be measured across the tops of the knurl and the minimum head diameter shall be the diameter of the unknurled
42、portion. The minimum head diameter should be measured just above the radius or chamfer at the bottom edge of the head, For nominal screw sizes 5 mm and larger, the heads shall be marked as specifed in para. 3.2. 2.1.2 Top of Head. The top of head, excluding socket, shall be flat and chamfered or rad
43、iused at the periphery. The .length of the chamfer or rounding measured on the side of the head shall not exceed the tabulated value for S given in Table 1. 2.1.3 Edge of Head. The edge between the bearing surface and the side of the head may be broken (rounded or chamfered), If broken, the radius o
44、r chamfer measured along the bearing surface shall not exceed the valueslisted for k in Table 1. 2.1.4 Bearing Surface. The plane of the bearing surface shall be perpendicular to the axis of the screw within a maximum deviation of 1 deg. 2.1.5 Head Concentricity. The head shall be con- centric with
45、the axis of the screw shank within an . amount equal to 2% of the basic screw diameter or 0.15 mm, whichever is greater, FIM (Full Indicator Movement). Concentricity shall be measured with the SOCKET HEAD CAP SCREWS (METRIC SERIES) screw being held within a distance equal to one screw diameter from
46、the underside of head but beyond the underhead fillet. 2.1.6 Underhead Fillet. For all lengths of screws the form of the fillet at junction of head and shank shall be optional within the following provisions. The fillet shall be a smooth and continuous concave curve fairing into the bearing surface
47、within the limits for diameter B, with a juncture radius of not less than F, and blending into the shank at a distance from the head not exceeding E, as determined at the basic screw diameter D. i 2.2 Sockets 2.2.1 Socket Type. Hexagon sockets shall be sup- plied, unless spline sockets are specified
48、 by the cus- tomer for screw sizes in which they are available. 2.2.2 Socket Size. Sockets shall be nominal size J for hexagon sockets and Mfor spline sockets specified in Table 1 for the corresponding screw size, and shall conform to the dimensions given in Tables 2 and 3, re- spectively, as determ
49、ined by gaging or measurement in accordance with para. 2.2.4, 2.2.3 Key Engagement. The key engagement depth shall conform to the minimum values specified for Tin Table 1 , as determined by gaging or measure- ment in accordance with para. 2.2.4. 2.2.4 Socket Gaging. Acceptability of hexagon sockets of nominal socket sizes up to and including 24 mm and all spline sockets shall be ascertained by the use of the socket gages specified in Tables 4 and 5, re- spectively.
