ASME B18.2.3.9M-2001

[Revis[iRonevoifsiAoNnSoIf/AASSMMEE B18.2.3.9M-1984 (R1995)]

METRIC HEAVY HEX FLANGE SCREWS

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

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 HEAVY HEX FLANGE

SCREWS

ASME B18.2.3.9M-2001

[Revision of ANSI/ASME B18.2.3.9M-1984 (R1995)]

Date of Issuance: September 17, 2001

This Standard will be revised when the Society approves the issuance of a new edition. There will be no addenda issued to this edition.

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The American Society of Mechanical Engineers Three Park Avenue, New York, NY 10016-5990

Copyright © 2001 by

THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS

All Rights Reserved Printed in U.S.A.

FOREWORD

American National Standards Committee B18 for the standardization of bolts, screws, nuts, rivets, and similar 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, Inc.), with the Society of Automotive Engineers and the American Society of Mechanical Engineers as joint sponsors. Subcommittee 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 responsibility for developing standards for metric hex bolts, screws, and nuts.

Following issuance of ANSI B18.2.3.4M-1979, interest developed in the farm equipment, heavy truck, and off-road vehicles industries for a second series of metric hex flange screws having a head widths across flats series equal to those of metric hex cap screws. During the analytical research study to optimize head proportions of hex flange screws (refer to the Foreword of ASME B18.2.3.4M-2000), this larger head series was also investigated, and appropriate values for the various head characteristics were established for screw sizes M10 through M20.

This new design of metric heavy hex flange screws was submitted by the United States of America/Canada to ISO/TC2 at its May 1982 meetings. TC2 accepted the proposal and authorized development of International Organization for Standardization (ISO) standards.

After these ISO decisions, Subcommittee 2 drafted this Standard.

This Standard was approved by letter ballot of the ASME B18 Standards Committee on April 18, 1983, and was subsequently approved by the American Society of Mechanical Engineers and submitted to the American National Standards Institute for designation as an American National Standard. This was granted on March 23, 1984. The Standard was reaffirmed in 1995. This draft revision was prepared based on revisions that were made in the metric hex cap screw standard in December 1998. This Standard was approved by the American National Standards Institute on March 9, 2001. The key revisions include the following:

1. The heavy hex series is expanded to include sizes M5, M6, and M8 with head dimensions adopted by ISO/DIS 8102.

2. All head heights (K) and wrenching heights (Kw) are increased to improve wrenchability.

3. The position of head-to-shank is changed to maximum material condition (MMC) as described in para. 11 and Tables 2 and 5.

4. The length tolerances are changed in Table 7 to agree with those of the draft of ASME B18.2.3.4M, Metric Hex Flange Screws.

5. Straightness is specified at MMC, and a rail gage replaces the sleeve gage as specified in para. 18.

6. The concavity angle of the conical bearing surface is now 0.75 deg ±0.50 deg to agree with that of ISO and to match B18.2.3.4M. The bearing face runout is to be measured on the actual bearing circle instead of the minimum bearing circle as specified in para. 13.

7. The transition threads shall have a rounded root contour per para. 20.4. This replaces,

   
   

   “For screws of Property Class 10.9 and higher strength materials (tensile strength 1040 MPa and higher) the transition threads shall have a rounded root contour no radius of which shall be less than the specified minimum at the root of the full form thread.”

8. The position of body-to-thread previously required is deleted based on the B18 Subcommittee 2 decision of December 2, 1998.

9. Appendix A is added to provide a detailed comparison with ISO/DIS 8102, with unpublished changes agreed upon in ISO/TC2/WG2. The current wrenching height formula in ISO 4759-1 would increase the wrenching heights even more. No support exists in North America for increases beyond those included herein.

   
   

   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

   1. D. Strong, Vice Chair

   2. W. Vass, Vice Chair

R. L. Crane, Secretary

COMMITTEE PERSONNEL

J. Altman, Rotor Clip Co.

J. H. Slass, Alternate, Rotor Clip Co.

J. B. Belford, Lawson Products, Inc.

J. A. Buda, SPS Technologies

R. M. Byrne, Trade Association Management, Inc.

D. A. Clever, Deere and Co.

A. P. Cockman, Ford Motor Co.

T. Collier, Cam-Tech Industries, Inc.

R. L. Crane, The American Society of Mechanical Engineers

1. C. DiCola, Wrought Washer Co.

2. A. Dusina, Federal Screw Works

D. S. George, Ford Motor Co.

D. L. Drobnich, Alternate, Ford Motor Co.

J. Greenslade, Greenslade and Co.

B. Hasiuk, Defense Industrial Supply Center

A. Herskovitz, U.S. Army

J. Hubbard, Rockford Fastener, Inc.

D. F. Kattler, SPS Technologies

J. F. Koehl, Spirol International Corp.

W. H. Kopke, ITW Shakeproof Assembly Co.

M. Levinson, Alternate, ITW Shakeproof Assembly Co.

J. G. Langenstein, Consultant

D. Liesche, Defense Industrial Supply Center

L. L. Lord, Caterpillar, Inc.

R. L. Tennis, Alternate, Caterpillar, Inc.

D. B. Mantas, GE—Empis

A. D. McCrindle, Genfast Manufacturing Co.

K. E. McCullough, Consultant

R. B. Meade, Textron Fastening Systems

M. D. Prasad, General Motors Corp.

S. Savoji, ITW Medalist

W. Schevey, BGM Fastener Co., Inc.

R. D. Strong, General Motors Corp.

J. F. Sullivan, National Fasteners Distribution Association

1. Torres, Action Threaded Production

2. W. Vass, Industrial Fasteners Institute

C. B. Wackrow, MNP Corp.

R. G. Weber, Fairfield University

W. K. Wilcox, Naval Sea Systems

1. J. Wilson, Industrial Fasteners Institute

2. R. Akers, Alternate, Industrial Fasteners Institute

R. B. Wright, Wright Tool Co.

J. G. Zeratsky, Tubular and Machine Institute

SUBCOMMITTEE 2 — EXTERNALLY DRIVEN FASTENERS

S. W. Vass, Chair, Lake Erie Screw Corp./Industrial Fasteners Institute

R. L. Crane, Secretary, The American Society of Mechanical Engineers

H. S. Brenner, Almay Research and Testing

R. M. Byrne, Trade Association Management, Inc.

M. M. Chu, Nucor Fastener

D. A. Clever, Deere and Co.

A. P. Cockman, Ford Motor Co.

R. J. Corbett, Huck International

E. R. Cossairt, Hill Fastener Corp.

D. L. Drobnich, Ford Motor Co.

B. A. Dusina, Federal Screw Works

D. S. George, Ford Motor Co.

J. Greenslade, Greenslade and Co.

A. Herskovitz, Consultant

M. W. Holubecki, Electric Boat Corp.

J. Hubbard, Rockford Fastener, Inc.

D. F. Kattler, SPS Technologies

D. Liesche, Defense Industrial Supply Center

L. L. Lord, Caterpillar, Inc.

D. B. Mantas, GE—Empis

A. D. McCrindle, Genfast Manufacturing Co.

K. E. McCullough, Consultant

1. B. Meade, Textron Fastening Systems

2. Savoji, ITW Medalist

J. A. Schlink, Caterpillar, Inc.

D. F. Sharp, Turnasure LLC

W. R. Stevens, MacLean–Fogg Fastening

R. D. Strong, General Motors Corp.

J. F. Sullivan, National Fasteners Distribution Association

D. M. Sutula, Industrial Fasteners Institute

R. L. Tennis, Caterpillar, Inc.

R. Torres, Action Threaded Products

C. B. Wackrow, MNP Corp.

W. L. Wilcox, Naval Sea Systems

C. J. Wilson, Industrial Fasteners Institute

CORRESPONDENCE WITH B18 COMMITTEE

General. ASME Standards are developed and maintained with the intent to represent the consensus of concerned interests. As such, users of this Standard may interact with the Committee by requesting interpretations, proposing revisions, and attending Committee meetings. Correspondence should be addressed to:

Secretary, B18 Standards Committee

The American Society of Mechanical Engineers Three Park Avenue

New York, NY 10016-5990

Proposing Revisions. Revisions are made periodically to the Standard to incorporate changes that appear necessary or desirable, as demonstrated by the experience gained from the application of the Standard. Approved revisions will be published periodically.

The Committee welcomes proposals for revisions to this Standard. Such proposals should be as specific as possible, citing the paragraph number(s), the proposed wording, and a detailed description of the reasons for the proposal, including any pertinent documentation.

Interpretations. Upon request, the B18 Committee will render an interpretation of any requirement of the Standard. Interpretations can only be rendered in response to a written request sent to the Secretary of the B18 Standards Committee.

The request for interpretation should be clear and unambiguous. It is further recommended that the inquirer submit his/her request in the following format:

Subject: Cite the applicable paragraph number(s) and the topic of the inquiry.

Edition: Cite the applicable edition of the Standard for which the interpretation is being requested.

Question: Phrase the question as a request for an interpretation of a specific requirement suitable for general understanding and use, not as a request for an approval of a proprietary design or situation. The inquirer may also include any plans or drawings which are necessary to explain the question; however, they should not contain proprietary names or information.

Requests that are not in this format will be rewritten in this format by the Committee prior to being answered, which may inadvertently change the intent of the original request. ASME procedures 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 “endorse” any item, construction, proprietary device,

or activity.

Attending Committee Meetings. The B18 Standards Committee regularly holds meetings, which are open to the public. Persons wishing to attend any meeting should contact the Secretary of the B18 Standards Committee.

CONTENTS

Foreword iii

Standards Committee Roster v

Correspondence With the B18 Committee vii

1. Scope 1

2. Comparison With ISO/DIS 8102 1

3. Referenced Standards 1

4. Terminology 2

5. Dimensions 2

6. Top of Head 2

7. Head Height 2

8. Wrenching Height 2

9. Corner Fill 2

10. Gaging of Heavy Hex Flange Head 2

11. Position of Head 2

12. Flange 2

13. Bearing Surface 2

14. Fillet 3

15. Body Diameter 3

16. Length 4

17. Points 4

18. Straightness 5

19. Threads 5

20. Thread Length 7

21. Materials and Mechanical Properties 9

22. Identification Symbols 9

23. Finish 10

24. Workmanship 10

25. Inspection and Quality Assurance 10

26. Dimensional Conformance 10

ASME B18.2.3.9M-2001

METRIC HEAVY HEX FLANGE SCREWS

1. SCOPE

   
   

   1. This Standard covers the complete dimensional and general data for metric series heavy hex flange screws recognized as American National Standard.

   2. The inclusion of dimensional data in this Standard is not intended to imply that all products described are stock production items. Consumers should consult with suppliers concerning availability of products.

      
      

2. COMPARISON WITH ISO/DIS 8102

   
   

   1. Heavy hex flange screws as presented in this standard are harmonized to the extent possible with the draft international standard ISO/DIS 8102, Hexagon Bolts With Flange—Heavy Series, and with revisions agreed to by ISO/TC2/WG2 in May 1989 in Zurich and later that have not been published in a revised draft. If it were published, the dimensional differences between this Standard and ISO/DIS 8102 would be few, relatively minor, and none would affect functional interchangeability of screws manufactured to the require- ments of either.

      This Standard specifies some requirements that are not included in ISO/DIS 8102. Dimensional requirements shown in bold type are in addition to, or differ from, ISO/DIS 8102. The technical differences between this standard and the ISO documents are described in Appendix A.

   2. Letter symbols designating dimensional charac- teristics are in accord with ISO 225, Fasteners—Bolts, Screws, Studs and Nuts—Symbols and Designations of Dimensions, and with ISO/DIS 8102, except where capitals have been used instead of lowercase letters used in the ISO standards.

      
      

3. REFERENCED STANDARDS

The following is a list of publications referenced in

ASME B1.3M Screw Thread Gaging Systems for Di- mensional Acceptability—Inch and Metric Threads (UN, UNR, UNJ, M, and MJ)

ASME B1.13M Metric Screw Threads—M Profile ASME B18.2.8 Clearance Holes for Inch and Metric

Bolts and Screws

ASME B18.12 Glossary of Terms for Mechanical Fas- teners

ASME B18.18.1M Inspection and Quality Assurance for General Purpose Fasteners

ASME B18.18.2M Inspection and Quality Assurance for High-Volume Machine Assembly Fasteners

ASME B18.24.1 Part Identifying Number (PIN) Code System Standard for B18 Externally Threaded Fas- teners

ASME Y14.5M Dimensioning and Tolerancing Publisher: American Society of Mechanical Engineers

(ASME International), Three Park Avenue, New

York, NY 10016-5990; Order Department: 22 Law Drive, Box 2300, Fairfield, NJ 07007

ASTM F 468M Nonferrous Bolts, Hex Cap Screws, and Stands for General Use (Metric)

ASTM F 568M Carbon and Alloy Steel Externally Threaded Metric Fasteners

ASTM F 738M Stainless Steel Metric Bolts, Screws, and Studs

ASTM F 788/F 788M Surface Discontinuities of Bolts, Screws and Studs, Inch and Metric Series

Publisher: American Society for Testing and Materials (ASTM), 100 Barr Harbor Drive, West Consho- hocken, PA 19428

ISO 225 Fasteners—Bolts, Screws, Studs and Nuts— Symbols and Designations of Dimensions1

ISO 3508 Thread Runouts for Fasteners With Thread in Accordance With ISO 261 and ISO 2621

ISO 4759-1 Tolerances for Fasteners—Part 1: Bolts, Screws and Nuts With Thread Diameters 1.6 to 150 mm and Product Grades A, B and C1

ISO/DIS 8102 Hexagon Bolts With Flange-Heavy Series1

this Standard. Unless otherwise specified, the standard(s)

referenced shall be the most recent issue at the time of order placement.

1 May also be obtained from American National Standards Institute, 11 West 42nd Street, New York, NY 10036.

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