1、AN AMERICAN NATIONAL STANDARD ASME B18.3-2012Revision of ASME B18.3-2003 (R2008)Socket Cap, Shoulder, Set Screws, and Hex Keys (Inch Series)ASME B18.3-2012Revision of ASME B18.3-2003 (R2008)Socket Cap,Shoulder, SetScrews, andHex Keys(Inch Series)AN AMERICAN NATIONAL STANDARDTwo Park Avenue New York,
2、 NY 10016 USADate of Issuance: April 24, 2013This Standard will be revised when the Society approves the issuance of a new edition.ASME issues written replies to inquiries concerning interpretations of technical aspects of thisStandard. Periodically certain actions of the ASME B18 Committee may be p
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11、,without the prior written permission of the publisher.The American Society of Mechanical EngineersTwo Park Avenue, New York, NY 10016-5990Copyright 2013 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.CONTENTSForeword ivCommittee Roster . viCorrespondence With the
12、B18 Committee vii1 Introductory Notes . 12 General Data 2Figure1 Cup Point Variations . 37Tables1 Dimensions of Hexagon Socket Head Cap Screws . 32 Dimensions of Under Head Fillets for Socket Head Cap Screws Threadedto the Head 63 Dimensions of Under Head Fillets for Socket Head Cap Screws With anUn
13、threaded Length of Body Diameter 74 Body and Grip Lengths for Socket Head Cap Screws 85 Lengths Beyond Sizes in Table 4 126 Shank Straightness for Socket Head Cap Screws . 137 Dimensions of Drilled Hexagon Socket Head Cap Screws 148 Dimensions of Hexagon Socket Flat Countersunk HeadCapScrews 169 Bod
14、y and Grip Lengths for Socket Flat Countersunk Head Cap Screws 1910 Lengths Beyond Sizes in Table 9 2211 Dimensions of Hexagon Socket Button Head Cap Screws 2312 Dimensions of Low Head Hexagon Socket Cap Screws 2613 Dimensions of Hexagon Socket Head Shoulder Screws 2814 Dimensions of Hexagon Socket
15、Set Screws 3115 Hexagon Key Engagements for Short Length Set Screws . 3516 Dimensions of Optional Cup Points . 3617 Dimensions of Hexagon Keys and Bits 3818 Dimensions of Hexagon Sockets 40Mandatory AppendicesI Gages and Gaging for Hexagon Sockets . 41II Protrusion Gaging of Flat Countersunk Heads .
16、 43III Type VI Recess Dimensions . 45Nonmandatory AppendicesA Drill and Counterbore Sizes for Socket Head Cap Screws 48B Formulas for Dimensions . 51C Hexagon Socket Head Cap Screws (1936 Series) . 53iiiFOREWORDAmerican National Standards Committee B18 for thestandardization of bolts, screws, nuts,
17、rivets, and similarfasteners was organized in March 1922 as SectionalCommittee B18 under the aegis of the AmericanEngineering Standards Committee (later the AmericanStandards Association, then the United States ofAmerica Standards Institute and, as of October 6, 1969,the American National Standards
18、Institute) with theSociety of Automotive Engineers and the AmericanSociety of Mechanical Engineers as joint sponsors.Subcommittee No. 91on Socket Head Cap and SetScrews was organized in April 1929 and completed itsfirst report in November 1931. Seven successive draftswere issued during which the con
19、tent of the proposalwas considerably extended and refined, and inMarch 1933, copies were distributed to industry for criti-cism and comment. The suggestions received were care-fully reviewed, and in April 1935, the proposal waspresented to the members of Sectional Committee B18for letter ballot vote
20、. Following the acceptance by thetwo sponsor organizations, it was designated as anAmerican Standard (ASA B18.3) in February 1936 bythe American Standards Association.For the purpose of keeping the work of theSubcommittee in line with the developments in industry,the Committee prepared a supplement
21、to the standardin the form of a table covering the dimensions of hexago-nal and fluted socket head shoulder screws (stripperbolts)optional,whichreceivedapprovaloftheAmericanStandards Association in April 1944 and was designatedASA B18.3a.In March 1945, the Subcommittee submitted certainfundamental c
22、hanges and additions to the Standard,and the Sectional Committee recommended issuance ofa completely revised standard. Following approval ofthe Sectional Committee, the revised document wasapproved by the sponsor organizations and theAmerican Standards Association and designated anAmerican Standard
23、in April 1947.In accordance with ASA procedure, a review of thestandard was undertaken in 1950 and certain additionalchanges were recommended by the Subcommittee. Capscrew sizes No. 0 and 1 and set screw sizes No. 0, 1, 2,3, and 4 were added to satisfy increasing demand fromvarious industries. Mater
24、ial, hardness, and thread fitwere included to provide a more complete standard. Adraft dated November 1951 was distributed to industry1As of April 1, 1966, Subcommittee 9 was redesignated asSubcommittee 3.ivfor criticism and comment. A further revision, datedNovember 1953, was presented to Sectional
25、 CommitteeB18 for letter ballot vote. Following approval of theSectional Committee and sponsors, the proposal wassubmitted to the American Standards Association. Itwas approved and designated an American Standardon August 26, 1954.Shortly after the 1954 standard was issued, work wasinitiated on the
26、development of standards covering flatcountersunk head cap screws, button head cap screws,andcapscrewsupto4in.indiameter.Astheseproposalsevolved with comments received from various indus-tries, it became evident that a major revision wasrequired, particularly in regard to insufficient bearingsurface
27、undertheheadonsomesizesaswellasincreasedsocket sizesto permit higherset-up torque.The resultingproposed revision was presented to SectionalCommittee B18 for letter ballot vote. Following approvalof the Sectional Committee and sponsors, the proposalwas submitted to the American Standards Association.
28、It was approved and designated an American Standardon December 21, 1961.Continued surveillance of the 1961 standard by theSubcommittee indicated by 1966 that a complete revi-sion of the document was necessary to provide recogni-tion of technical improvements in materials andmanufacturing methods. Wo
29、rk over the next 2 yearsculminatedinaMarch 1968draftproposalincorporatingrevisions in the following areas:(a) more clearly defined materials for all products(b) application of Unified radius root threads to allcap screws(c) refinements to underhead fillets(d) extension of size coverage for flat coun
30、tersunkhead cap screws to include78in. through 112in. diame-ters, and tabulation of body and grip lengths for sizes0 in. through 1 in.(e) increased key engagements in socket set screwsand implementation of minimum hexagon key engage-ment in short length set screws(f) addition of width across corner
31、dimensions forhexagon keys and bits(g) the inclusion of appendices covering drill andcounterbore sizes for socket head cap screws(1960 Series), and gages and gaging for spline sockets.Following acceptance of this draft by theSubcommittee, it was approved by letter ballot ofUSA Standards Committee B1
32、8 and the sponsor organi-zations, and submitted to the United States of AmericaStandards Institute. It was approved and designated aUSA Standard on September 19, 1969.A periodic review of the standard, undertaken bySubcommittee 3 in 1973, resulted in agreement that thedocument be revised to reflect
33、clarification of theunderhead fillet on socket head cap screws, add cover-age on drilled socket head cap screws, lengthen thethread undercut on socket head shoulder screws, andextend the coverage on the latter to include the 112-in.,134-in., and 2-in. sizes. A proposal incorporating thesechanges tog
34、ether with numerous editorial correctionswas prepared and, subsequent to Subcommittee accept-ance, approved by letter ballot to American NationalStandards Committee B18. Following approval by thesponsor organizations, the proposal was submitted tothe American National Standards Institute and desig-n
35、ated an American National Standard onNovember 1, 1976.A periodic review of the standard, undertaken by theSubcommittee in 1980, resulted in agreement that thedocument be revised(a) to clarify the notes on screw point chamfers(b) in socket tolerances for large sockets and in coun-terbore sizes to ref
36、lect standard tooling(c) to reference ASTM A574 for the appropriatemechanical and chemical requirementsA proposal containing these changes, as well as manyeditorial corrections, was prepared for and balloted byletter ballot to the ASME Committee B18. Followingapproval by the sponsor organization, th
37、e proposal wassubmitted to the American National Standards Instituteand designated an American National Standard onJanuary 4, 1982.A periodic review of the standard, undertaken bythe Committee in 1985, resulted in agreement that thedocument be revised to clarify the dimensions withrespect to plated
38、products, and to incorporate by refer-ence the new ASTM documents for the appropriatemechanical, chemical, and testing requirements for thebutton head, flat countersunk head, and set screw prod-ucts. A proposal containing these changes, as well aseditorial corrections,was preparedand ballotedby lett
39、erballot to ASME Committee B18. Following approval byASME, the proposal was submitted to the AmericanNational Standards Institute and designated anAmerican National Standard on August 7, 1986.A periodic review of this Standard was undertakenby the Committee in 1990. Based on this review, it wasvdete
40、rmined that the document needed significant revi-sions to clarify and update the Standard. These revisionswould need to address the technical changes in manu-facturing methods and changes in the standards com-munity. To accomplish this objective, established qualitystandards were recognized and inte
41、grated into theStandard. In addition, designated characteristics foreach product and product identification were estab-lished and gaging techniques for countersunk screwswere added. These changes were balloted and approvedby the ASME B18 Committee. The proposal was submit-ted to the American Nationa
42、l Standards Institute anddesignated an American National Standard onJanuary 14, 1998.A periodic review of this Standard was again under-taken by the Committee in 2000. It was determined thatthere were many technical printing errors that had tobe revised. Inspection definitions were added to clarifyb
43、earing surface, runout, and straightness for variousproducts. The radius under the head for socket headscrews was clarified by the addition of drawings show-ing the radius on thread to the head socket screws, andalso showing the radius on socket screws with anunthreaded shoulder. The protrusion gage
44、 dimensionswere changed on flat head socket cap screws. The threadrequirements for short length socket set screws werealso changed. A standard was also developed for lowhead socket cap screws. These changes were ballotedand approved by the ASME B18 Committee. The pro-posal was submitted to the Ameri
45、can NationalStandards Institute and designated as an AmericanNational Standard on July 8, 2003.In 2010, a task group was formed to review thisStandard. The current revision is a result of their work.Spline driven fasteners, and their associated keys, havebeen removed from the document and users that
46、 wishto use this type of fastener will need to refer to theprevious edition. The Type VI (Six Lobe) drive style hasbeen added as a mandatory appendix. The tolerance forprotrusion requirements on flat head socket cap screwshas been increased. An alternative method for measur-ing protrusion has been i
47、ncluded and corresponds withthe metric document ISO 10642.Other less significant changes in this revision includethe addition of some sizes and slight changes to therequirements for drilled heads.This Standard was approved by the AmericanNational Standards Institute on November 16, 2012.ASME B18 COM
48、MITTEEStandardization of Bolts, Nuts, Rivets, Screws, Washers, andSimilar Fasteners(The following is the roster of the Committee at the time of approval of this Standard.)STANDARDS COMMITTEE OFFICERSJ. Greenslade, ChairD. S. George, Vice ChairW. H. King, Vice ChairC. J. Gomez, SecretarySTANDARDS COM
49、MITTEE PERSONNELV. Cartina, NylokD. A. Clever, Contributing Member, ConsultantA. P. Cockman, Ford Motor Co.C. D. de la Garza, TSP, Inc.D. S. George, Ramco SpecialtiesC. J. Gomez, The American Society of Mechanical EngineersJ. Greenslade, Industrial Fasteners InstituteJ. J. Grey, Contributing Member, Fastener Consulting Services, Inc.A. Herskovitz, Contributing Member, ConsultantJ. Hubbard, Leland-Powell Fasteners, Inc.J. Jennings, Contributing Member, Naval Surface Warfare CenterW. H. King, Porteous Fastener Co.SUBCOMMITTEE 3 SOCKET HEAD, CAP, AND SET SCREWSC. B. Williamson,
