1、COPYRIGHT American Society of Mechanical Engineers Licensed by Information Handling Services COPYRIGHT American Society of Mechanical Engineers Licensed by Information Handling Services The American Society of Mechanical Engineers A N A M E R I C A N N A T I O N A L S T A N D A R D METRIC HEX CAP SC

2、REWS ASME B 1 8 m L 3 m l M - I f i l l Revision 01 A N S I I 1 8.2.3.1 M-1979 (RlNfl5) COPYRIGHT American Society of Mechanical Engineers Licensed by Information Handling Services COPYRIGHT American Society of Mechanical Engineers Licensed by Information Handling Services Date of Issuance: December

3、 31, 1999 The 1998 edition of this Standard is being issued with an automatic addenda subscription service. The use of an addenda allows revisions made in response to public review comments or committee actions to be published as necessary. The next edition of this Standard is scheduled for publicat

4、ion in 2004. ASME is the registered trademark of The American Society of Mechanical Engineers. This code or standard was developed under procedures accredited as meeting the criteria for American National Standards. The Standards Committee that approved the code or standard was balanced to assure th

5、at individuals from competent and concerned interests have had an opportunity to participate. The proposed code or standard was made available for public review and comment that provides an opportunity for additional public input from industry, academia, regulatory agencies, and the public-at-large.

6、 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 st

7、andard 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

8、. Participation by federal agency representativeb) or person(s) 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 of this document issued in accordance with the established ASME

9、 procedures and policies, which precludes the issuance of interpretations by individuals. 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. The American Society of Mechanical Engineers Three

10、Park Avenue, New York, NY 10016-5990 Copyright Q 1999 by THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS All Rights Reserved Printed in U.S.A. COPYRIGHT American Society of Mechanical Engineers Licensed by Information Handling Services COPYRIGHT American Society of Mechanical Engineers Licensed by Info

11、rmation Handling Services w w w . b z f x w . c o m FOREWORD American National Standards Committee B 18 for the standardization of bolts, screws, nuts, rivets, and similar fasteners was organized in March of 1922, as Sectional Committee B18 under the aegis of the American Engineering Standards Commi

12、ttee (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 Automotive Engineers and the American Society of Mechanical Engineers as joint sponsors. Subcommitte

13、e 2 was subsequently established and charged with the responsibility for technical content of standards covering wrench head bolts and nuts. At its meeting on December 4, 1974, Committee B18 authorized preparation of a series of standards for metric fasteners. Subcommittee 2 was assigned responsibil

14、ity for developing standards for metric hex bolts, screws, and nuts. On September 22, 1976, Subcommittee 2 organized the contents of a standard covering eight different hex head screw and bolt products. Actual drafting was postponed until ISO/TC2 could reach final decisions relating to the basic dim

15、ensions and characteristics of hex bolts, screws, and nuts. At ISO/TC2 meetings held in April of 1977, final actions were taken. Committee B18 affirmed the TC2 decisions at a meeting on June 29, 1977, and drafting of this Standard was started. Committee B 18, in February of 1978, established a coope

16、rative program with the Department of Defense to draft American National Standards for metric fasteners in such a way that they could be used directly by the Government for procurement purposes. The Department of Defense requested that each of the eight products be covered in separate standards, and

17、 Subcommittee 2 accepted this approach at its meeting on June 27, 1978. This Standard was approved by letter ballot of Committee B 18 on September 15, 1978, and was subsequently approved by the secretariat and submitted to the American National Standards Institute for designation as an American Nati

18、onal Standard. This was granted on April 26, 1979. B 18.2.3.1M was subsequently reaffirmed in 1989 and again in 1995. In 1997, a revision was intiated to try and align this Standard with its IS0 counterpart. A letter ballot, which closed in November of 1998, was not approved and in early December of

19、 1998, Subcommittee 2 met to resolve the negatives. As part of the resolution of these negatives, it was agreed to include in this Foreword a summary of key changes to this Standard. The following is that summary: It was made clear in para. 1.4.1 that all dimensions in this Standard apply before any

20、 coating has been applied. The washer face diameter is now to be inspected a 0.1 mm above the bearing plane and not at midthickness as it was previously. The length of point was redefined, including a new method for checking an increased maximum point length defined in para. 2.5 and Table 5. Screw s

21、traightness, which formerly was checked with a sleeve gage, is now checked with a rail gage as established in para. 2.6. The position of body-to-thread, which is checked with a sleeve gage, now applies only to cut threads as established in para. 2.7.6, with new tolerance zone values shown in Table 1

22、. Grip length and body length were revised to correspond to the IS0 standard. This results in the following standard diameterllength combinations being fully threaded and not partially threaded as they were previously: . 111 COPYRIGHT American Society of Mechanical Engineers Licensed by Information

23、Handling Services COPYRIGHT American Society of Mechanical Engineers Licensed by Information Handling Services w w w . b z f x w . c o m M8 x 35 MI0 x 40 MI2 x 45 MI4 x 50 MI4 x 55 MI6 x 55 MI6 x 60 M20 x 65 M20 x 70 M24 x 80 M30 x 100 M36 x 110 M36 x 120 M36 x 130 M42 x 150 M42 x 140 M42 x 130 M42

24、x 120 M48 x 160 M48 x 150 M56 x 200 M56 x 180 M64 x 240 M64 x 220 M64 x 200 M90 x 300 M72 x 260 M90 x 280 M72 x 240 M90 x 260 M72 x 220 MI00 x 340 M80 x 280 MI00 x 320 M80 x 260 MI00 x 300 M80 x 240 MI00 x 280 M90 x 320 For screws threaded full length, the grip length was increased approximately to

25、3 times pitch from 2.5 times pitch (see Table 6). The previous requirement for a controlled root radius in the runout section of the thread on products of Property Class 10.9 or greater was replaced by a requirement for a rounded root contour included in para. 2.7.5. Quality assurance and dimensiona

26、l conformance have been specified and included in paras. 2.13 and 2.14, respectively. Appendix IV provides a detailed comparison o f product characteristics in this Standard as compared to those of KO. Users of this Standard are urged to review its contents carefully so that no confusion exists with

27、 the provisions of the previous editions of this Standard. This revision was approved as an American National Standard on May 10, 1999. iv COPYRIGHT American Society of Mechanical Engineers Licensed by Information Handling Services COPYRIGHT American Society of Mechanical Engineers Licensed by Infor

28、mation Handling Services w w w . b z f x w . c o m ASME B18 STANDARDS COMMITTEE 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 D. A. Clever, Chair R. D. Strong, Vice Chai

29、r S. W. Vass, Vice Chair R. L. Crane, Secretary COMMITTEE PERSONNEL J. C. Akins, Safety Socket Screw Corp. J. Altman, Rotor Clip Co. J. H. Slass, Alternate, Rotor Clip J. B. Belford, Lawson Products Inc. D. Broomfield, Illinois Tool Works Inc. J. A. Buda, SPS Technologies D. A. Clever, Deere and Co.

30、 T. Collier, Cam-Tech Industries Inc. R. L. Crane, The American Society of Mechanical Engineers A. C. DiCola, Wrought Washer Co. A. Dinh, Defense Industrial Supply Center W. D. Downing, Emhart Heli-Coil B. A. Dusina, Federal Screw Works D. S. George, Ford Motor Co. D. L. Drobnich, Alternate, Ford Mo

31、tor Co. J. Greenslade, Greenslade however, they should not contain proprietary names or information. Requests that are not in this format may be rewritten in the appropriate format by the Committee prior to being answered, which may inadvertently change the intent of the original request. ASME proce

32、dures provide for reconsideration of any interpretation when or if additional information that might affect an interpretation is available. Further, persons aggrieved by an interpretation may appeal to the cognizant ASME Committee or Subcommittee. ASME does not “approve,” “certify,” “rate,” or “endo

33、rse” any item, construction, proprietary device, or activity. Atfending Cornmiltee Meetings. The B I8 Main Committee regularly holds meetings, which are open to the public. Persons wishing to attend any meeting should contact the Secretary of the B18 Main Committee. vii COPYRIGHT American Society of

34、 Mechanical Engineers Licensed by Information Handling Services COPYRIGHT American Society of Mechanical Engineers Licensed by Information Handling Services Foreword . Standards Committee Roster . Correspondence With the B18 Committee . 1 Introductory Notes . 2 General Data . Figures 1 Washer Face D

35、etail . 2 Fillet Detail for Short Screws . 3 Fillet Detail for Long Screws . Tables 1 Tolerance Zones . 2 Dimensions of Underhead Fillets . 3 Dimensions of Hex Cap Screws . 4 Thread Lengths . 5 Dimensions of Points . 6 Maximum Grip Gaging Lengths Lg and Minimum Body Lengths L. . 7 Thread Lengths . N

36、onmandatory Appendices A Screw Straightness Gage and Gaging Procedure . B Body Position Gages and Gaging Procedures . C Recommended Clearance Holes for Screws . . 111 V vii 1 2 3 4 5 3 5 6 8 8 10 12 13 15 17 D Comparison With IS0 Standards . 19 ix COPYRIGHT American Society of Mechanical Engineers L

37、icensed by Information Handling Services COPYRIGHT American Society of Mechanical Engineers Licensed by Information Handling Services ASME B18.2.3.1M-1999 METRIC HEX CAP SCREWS 1 INTRODUCTORY NOTES 1.1 Scope 1.1.1 This Standard covers the complete general and dimensional data for metric series hex c

38、ap screws recognized as American National Standard. 1.1.2 The inclusion of dimensional data in this Standard is not intended to imply that all of the sizes in conjunction with the various options described herein are stock items. Consumers should consult with suppliers concerning lists of stock prod

39、uction hex cap screws. 1.2 Comparison With IS0 Standards 1.2.1 Hex cap screws, sizes M5 to MU, as presented in this Standard are harmonized to the extent possible with IS0 4014 or, for short screws threaded full length, with IS0 4017. Dimensional differences between this Standard and IS0 4014 or IS0

40、 4017 are few, relatively minor, and none will affect the functional interchange- ability of screws manufactured to the requirements of either. The following functional characteristics of screws, sizes M5 through MI4 with nominal lengths 2 times diameter through IO times diameter, sizes MI6 through

41、M24 with nominal lengths 2 times diameter through 150 mm, and sizes M30 through M64 with nominal lengths 2 times diameter and longer, are in agreement between this Standard and IS0 4014 or IS0 4017, as applicable: (a) nominal diameters and thread pitches, (6) body diameters, (c) widths across flats

42、and comers (see para. 1.2.5), (d) nominal head heights, (e) nominal lengths and thread lengths, and (f) thread dimensions. This Standard omits sizes MI .6-M4, MI 8, M22, M21, M33, M39, M45, M52, and M60, which are included in IS0 4014 and IS0 4017. This Standard includes sizes MI0 x I .5 with 15 mm

43、width across flats, M72 x 6, M80 x 6, M90 x 6, and MlOO x 6, which are not in IS0 4014 or IS0 4017. This Standard specifies some requirements that are not included in IS0 4014 or IS0 4017. Dimensional requirements shown in bold type within the text and where noted within tables differ from, or are i

44、n addition to, IS0 4014 and/or IS0 4017, or, for sizes over M64, other relevant nonproduct IS0 stan- dards. The technical differences between this Standard and the IS0 standards are summarized in Appendix IV. 1.2.2 At its meeting in Varna in May of 1977, ISO/ TC2 studied several technical reports an

45、alyzing design considerations influencing determination of the best series of width across flats for hexagon bolts, screws, and nuts. A primary technical objective was to achieve a logical ratio between the head or nut bearing surface area (which determines the magnitude of the compres- sive stress

46、on the bolted members) and the tensile stress area of the screw thread (which governs the clamping force that can be developed by tightening the fastener). MI0 screws with 15 mm width across flats are currently being produced and used in the U.S. and many other countries of the world. This size, how

47、ever, is not an IS0 standard. Unless M IO screws with 15 mm width across flats are specifically ordered, MI0 screws with 16 mm width across flats shall be furnished. 1.2.3 Letter symbols designating dimensional charac- teristics are in accord with IS0 225, IS0 4014, and IS0 4017, except where capita

48、ls have been used instead of the lower case letters used in the IS0 standards. 1.3 Terminology For definitions of terms relating to fasteners or compo- nent features thereof used in this Standard, refer to ASME B18.12. 1.4 Dimensions 1.4.1 All dimensions in this Standard are in millime- ters (mm) an

49、d apply before any coating, unless stated otherwise. I COPYRIGHT American Society of Mechanical Engineers Licensed by Information Handling Services COPYRIGHT American Society of Mechanical Engineers Licensed by Information Handling Services ASME B18.2.3.1M-1999 METRIC HEX CAP SCREWS 1.4.2 Symbols sp

50、ecifying geometric characteristics are in accord with ASME Y14.5M. 1.5 References The following is a list of publications referenced in this Standard. Unless otherwise specified, the referenced standard shall be the most recent issue at the time of order placement. ASME B 1.3M, Screw Thread Gaging S

51、ystems for Dimensional Acceptability - Inch and Metric Screw Threads (UN, UNR, UNJ, M, and MJ) ASME BI. l3M, Metric Screw Thread - M Profile ASME B4.2, Preferred Metric Limits and Fits ASME B 18.12, Glossary of Terms for Mechanical Fasteners ASME B 18.18.1 M, Inspection and Quality Assurance for Gen

52、eral Purpose Fasteners ASME B 18.18.2M, Inspection and Quality Assurance for High-Volume Machine Assembly Fasteners ASME B 18.18.3M. Inspection and Quality Assurance for Special Purpose Fasteners ASME B 18.18.4M, Inspection and Quality Assurance for Fasteners for Highly Specialized Engineered Ap- pl

53、ications ASME B 18. I8.5M, Inspection and Quality Assurance Plan Requiring In-Process Inspection and Controls ASME B18.18.6M, Quality Assurance Plan for Fasten- ers Produced in a Third Party Accreditation System ASME B 18. 18.7M, Quality Assurance Plan for Fasten- ers Produced in a Customer Approved

54、 Control Plan ASME B 18.24.1, Part Identifying Number (PIN) Code System Standard for B 18 Externally Threaded Products ASME Y 14.5M. Dimensioning and Tolerancing Publisher: The American Society of Mechanical Engi- neers (ASME), Three Park Avenue, New York, NY 10016-5990; Order Department: Box 2300,

55、Fairfield, NJ 07007-2300. ASTM B 633, Electrodeposited Coatings of Zinc on ASTM F 468M, Specification for Nonferrous Bolts, Hex Cap Screws, and Studs for General Use - Metric ASTM F 568M, Specification for Carbon and Alloy ASTM F 738M, Specification for Stainless Steel Metric ASTM F 788F 788M, Surfa

56、ce Discontinuities of Bolts, Iron and Steel Steel Externally Threaded Metric Fasteners Bolts, Screws, and Studs Screws, and Studs, Inch and Metric Series ASTM F 871M, Standard Specification for Elec- trodeposited Coatings on Threaded Components Metric ASTM F 1137, Standard Specification for Phosphate/Oil and Phosphate/Organic Corrosion Protective Coatings for Fasteners ASTM F 1470, Standard Guide for Fastener Sampling for Specified Mechanical Propertics and Performance Inspection Publisher: American Society for Testing and M