1、ASME B18.6.7M-1999 Revision of ASME B18.6.7M-1985 (1993)l METRIC MACHINE SCREWS AN AMERICAN NAT - - - ONAL STANDARD The American Society of Mechanical Engineers The American Society of Mechanical Engineers AN - AMERICAN NATIONAL STANDARD METRIC MAEH SCREWS ASME B18.6.7M-1 U19 RIWBII 01 ASME B18.6.7M
2、-1885 (1 183) Date of Issuance: August 23, 2000 The 2000 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 t
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10、ork, NY 10016-5990 Copyright 2000 by THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS All Rights Reserved Printed in U.S.A. STD-ASME B1B-b-7M-ENGL 2000 0759b70 Ob17911 723 FOREWORD ASME Standards Committee BI8 for the standardization of bolts, screws, nuts, rivets and similar fasteners was organized in
11、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, 1 969, the American National Standards Institute, Inc.). The Society of Automo
12、tive Engineers and the American Society of Mechanical Engineers served as joint sponsors. Subcommittee 3 was subsequently established and charged with the responsibility for technical content of standards covering slotted and recessed head screws. In accordance with a general realignment of the subc
13、ommittee structure on April i, 1966, Subcommittee 3 was redesignated Subcommittee 6. At its meeting on December 4, 1974, Standards Committee BI8 authorized preparation of a series of standards for metric fasteners. Subcommittee 6 was responsible for developing product standards covering metric machi
14、ne screws and tapping screws. In subsequent meetings of Subcommittee 6, held over the ensuing two years, the content of the proposed metric standards was discussed and organized. It was decided that the coverage should be limited to the flat countersunk, oval countersunk, and pan head styles having
15、slotted and Types I and IA cross recessed drive provisions and the hex and hex washer head designs. The machine screws would cover sizes M2 through MI2 and, in steel, be available in two strength grades conforming to property classes 4.8 and 9.8. Also, it was the consensus that the respective head e
16、nvelopes for both machine screws and tapping screws of comparable sizes should remain consistent with established inch practices. In 1976, the Industrial Fasteners Institute published IFI-5 13, documenting dimensions and specifications as then agreed upon and coordinated to the extent possible with
17、the International Organization for Standardization (ISO) proposals, which Subcommittee 6 authorized as a first draft proposal for the metric machine screw document. Because the common head for machine and tapping screw approach differed considerably from existing metric practices and IS0 drafts, par
18、ticularly in regard to countersunk heads, a task group was established at the September 1977 meeting of the Subcommittee to develop proportions for a common 90 deg flat countersunk recessed head having adequate head to shank strength combined with satisfactory driveability. Also at this meeting, it
19、was recommended that consideration be given to developing a hex flange head having a smaller hex width across flats, similar to the metric hex flange screws evolving under Subcommittee 2 for larger product sizes. This head would be applicable to both machine and tapping screws and intended to replac
20、e the hex washer head, which in some sizes, was difficult to manufacture and had less than desirable driving capabilities. Over the ensuing years, the recommendations resulting from the task group studies along with other actions taken by Subcommittee 6 were coordinated through Subcommittee 4 with t
21、he appropriate ISOnC2 working groups toward resolution of dimensional differences. At the March 1980 meeting of ISOiTC2, a tentative agreement was reached on the envelopes for the flat, oval, pan, and hex heads. These actions were confirmed by Subcommittee 6 at the October 22, 1980 meeting and a rev
22、iew of the cross recess dimensions was initiated. At the December 9, 1981 meeting the Subcommittee, following approval of the proposed format, authorized preparation of a formal draft standard that would include substituting the hex flange head for the hex washer head. iii STD-ASIE BLB.b-7M-ENGL 200
23、0 0759b70 Ob17932 bbT In May 26, 1982 it was agreed to add a short shoulder under the head of heat treated flat countersunk head screws and approval was granted for numerous other refinements. A proposed draft of the standard was prepared and approved by letter ballot to Subcommittee 6 and ASME Stan
24、dards of Committee BI8 in December 17, 1984. Following acceptance by these respective groups, this proposal was approved by the sponsors and submitted by the ASME Board of Standardization to the American National Standards Institute. It was approved and formally designated an American National Stand
25、ard in July 23, 1985. In 1997, Subcommittee 6 initiated work to revise the head diameters for flat head screws, length measurement method for oval head screws, height inspection for oval head screws, and quality assurance. Protrusion height inspection for oval head screws was also added. These chang
26、es were balloted and approved by the ASME B 18 Committee. The proposal was submitted to the American National Standards Institute and designated an American National Standard in August 19, 1999. iv ASME STANDARDS COMMITTEE BI8 Standardization of Bolts, Nuts, Rivets, Screws, Washers, and Similar Fast
27、eners (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 Chair 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, Alterna
28、te. Rotor Clip Co. J. B. Belford, Lawson Products, Inc. D. Broomfield, ITW Shakeproof Industrial Products J. A. Buda, SPS Technologies D. A. Clever, Deere and Co. T. Collier, Cam-Tech Industries, Inc. R. L. Crane, The American Society of Mechanical Engineers A. C. Dcola, Wrought Washer Manufacturing
29、, Inc. A. Dinh, Defense Industrial Supply Center W. D. Downing, Consultant D. L. Drobnich, Ford Motor Co. B. A. Dutina, Federal Screw Works D. S. George, Ford Motor Co. A. Herskovitz, Consultant B. Hasiuk, Defense Industrial Supply Center A. C. Hood, ACH Technologies J. Hubbard, Rockford Fastener, I
30、nc. F. W. Kern, Society of Automotive Engineers J. F. Koehl, Spirol International Corp. W. H. Kopke, ITW Shakeproof Industrial Products J. G. Langenstein. Caterpillar, Inc. M. Levinson, ITW Shakeproof Industrial Products L. L. Lord, Caterpillar, Inc. A. D. McCrindle, Genfast Manufacturing Co. K. E.
31、McCullough, Consultant R. F. Novotny, Textron W. Schevey, BGM Fastener Co., Inc. R. D. Strong, General Motors Corp. J. F. Sullivan, Accurate Fasteners, Inc. R. L. Tennis, Caterpillar, Inc. S. W. Vass. Lake Erie Screw Corp./lFI C. B. Wackrow, MNP Corp. R. G. Weber, BEI School of Engineering, Fairfiel
32、d University W. K. Wilcox, Naval Sea Systems Command C. J. Wilson, Industrial Fasteners Institute V STDmASME BLB-b*7N-ENGL 2000 0759b70 Ob17914 432 m SUBCOMMITTEE 6 - SLOTTED AND RECESSED HEAD SCREWS R. D. Strong, Chair, General Motors Corp. R. L. Crane, Secretary, The American Society of Mechanical
33、 Engineers O. Broomfieid, ITW Shakeproof Industrial Products O. A. Clever, Deere and Co. M. Dailey, Barnes 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 inad
34、vertently 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 Sub
35、committee. ASME does not “approve,” “certify,” “rate,” or “endorse” any item, construction, proprietary device, or activity. Attending Committee Meetings. The B 18 Main Committee regularly holds meetings, which are open to the public. Persons wishing to attend any meeting should contact the Secretar
36、y of the Bi8 Main Committee. vii . STD-ASME BLB-b.3M-ENGL 2000 0759b70 ObL77L7 $41 CONTENTS Foreword Committee Roster Correspondence With the B 18 Committee . 1 Introductory Notes . 1.1 Scope . 1.2 Comparison With IS0 Standards 1.3 Head Types . 1.4 Dimensions 1.5 Options . 1.6 Terminology . 1.7 Desi
37、gnation 1.8 Clearance Holes . 1.9 Reference Standards 1 . 10 Inspection and Quality Assurance . 2 General Data 2.1 Screw Heads 2.2 Length 2.3 Threads . 2.4 Thread Length . 2.5 Body Diameter 2.6 Points . 2.7 Straightness . 2.8 Materials 2.9 Finish . 2.1 O Workmanship Tables 1 Thread Lengths for Machi
38、ne Screws 2 Dimensions of Slotted Fiat Countersunk Head Machine Screws . 3 Screws 4 Screws . 5 Screws 6 Dimensions of Slotted Oval Countersunk Head Machine Screws 7 Screws 8 Screws Dimensions of Type I Cross-Recessed Flat Countersunk Head Machine Dimensions of Type IA Cross-Recessed Flat Countersunk
39、 Head Machine Dimensions of Type III Square-Recessed Flat Countersunk Head Machine Dimensions of Type I Cross-Recessed Oval Countersunk Head Machine Dimensions of Type IA Cross-Recessed Oval Countersunk Head Machine iii vi V 1 1 1 1 2 2 2 2 2 2 3 3 3 4 4 4 4 4 4 4 5 5 6 7 8 10 12 14 15 17 iX Previou
40、s page is blank . = 0759b70 Ob17916 086 9 10 11 12 13 14 15 16 17 Dimensions of Type III Square-Recessed Oval Countersunk Head Machine Screws 19 Dimensions of Slotted Pan Head Machine Screws . 21 Dimensions of Type I Cross-Recessed Pan Head Machine Screws 22 Dimensions of Type IA Cross-Recessed Pan
41、Head Machine Screws . 23 Dimensions of Type III Square-Recessed Pan Head Machine Screws 24 Dimensions of Hex Head Machine Screws 25 Dimensions of Header Points for Machine Screws Before Threading 27 Recommended Nominal Screw Lenghts for Machine Screws 28 Dimensions of Hex Flange Head Machine Screws
42、. 26 Mandatory Appendices I Protrusion Gaging of Flat and Oval Countersunk Heads II Across-Comers Gaging of Hex Heads . 31 III Penetration Gaging of Recessed Heads 33 IV Wobble and Fit Gaging of Recessed Heads . 39 V Recommended Clearance Holes for Metric Machine Screws 43 29 X A 1 ASME B18.6.7M-199
43、9 METRIC MACHINE SCREWS 1 INTRODUCTORY NOTES 1.1 Scope 1.1.1 This Standard covers the complete general and dimensional data for metric flat countersunk, oval countersunk and pan slotted and recessed head machine screws, and metric hex and hex flange head machine screws recognized as standard. Also i
44、ncluded are appen- dices that provide specifications and instructions for protrusion gaging of flat countersunk head screws, across-comers gaging of hex head screws, and penetra- tion gaging and wobble gaging of recessed head screws, and clearance hole recommendations. 1.1.2 The inclusion of dimensi
45、onal data in this Standard is not intended to imply that all of the products described are stock production sizes. Consumers should consult with manufacturers concerning the availability of products. The recommended diameter-length combi- nations applicable to metric machine screws are shown in Tabl
46、e 17. 1.2 Comparison With IS0 Standards 1.2.1 The dimensions for flat countersunk, oval countersunk, pan, and hex head machine screws as presented in this Standard have been coordinated to the extent possible with IS0 standards. Where applica- ble, the comparable IS0 standard is referenced in the fo
47、otnotes to the dimensional tables for the respective screw products. Except for the recessed flat countersunk heads, the dimensional differences between machine screws covered in this Standard and those in IS0 standards are very few and relatively minor. None will affect the functional interchangeab
48、ility of screws manufactured to the requirements of either. For recessed flat countersunk head screws, the head envelopes are identical in both standards. One IS0 standard incorpo- rates shallower recesses without a shoulder and another IS0 standard, identical to this ASME Standard, is being drafted
49、. However, heat-treated products covered by this document feature a short shoulder under the head (with an attendant increase in the minimum grip length) and recess depths consistent with other head styles. 1.2.2 Hex flange head screws and screws implement- ing the Type III recess are not, as of this writing, covered by IS0 standards. 1.2.3 The Types I and IA cross-recesses documented in this Standard are designated Types H and Z, respec- tively, in corresponding IS0 standards. 1.2.4 Nominal screw lengths of 12-mm and 14-mm are recognized as IS0 standard lengths. The 13-mm length
