1、AN AMERICAN NATIONAL STANDARD ASME B18.2.1-2012Square, Hex, Heavy Hex, and Askew Head Bolts and Hex, Heavy Hex, Hex Flange, Lobed Head, and Lag Screws (Inch Series)(Revision of ASME B18.2.1-2010)ErratatoASME B18.2.1-2012Square, Hex, Heavy Hex, and Askew Head Boltsand Hex, Heavy Hex, Hex Flange, Lobe
2、d Head,and Lag Screws (Inch Series)The errata corrections listed below apply to ASME B18.2.1-2012. These corrections will beincorporated into the next edition of B18.2.1.Page Location Change15 Table 8 In Note (3), formula for “LG, max.”corrected (see overleaf)19 4.9(c)(1) “SAE” corrected to read “SA
3、E J429”24 Table 14 Datum “A” added to straightness callout forconsistency with Tables 1, 3, 4, 5, 7, and 8(see overleaf)THE AMERICAN SOCIETY OF MECHANICAL ENGINEERSTwo Park Avenue, New York, NY 10016-5990July 2013M4412Ep. 1 of 2 07-11-13 17:26:29 Textfile: 001109E001 Unit: UE01Table 8 Dimensions of
4、Hex Flange Screws (Contd)Maximum TransitionMaximumRing T Ring BBasic Thread Length, LTThread Length, YRunoutNote (3) Notes (3) and (4) Inside InsideNominal Size ofDiameter Diameter Thicknessor Basic Major Minimum Bearing For Screws For Screws For Screws For ScrewsDiameter of Bearing Surface With L W
5、ith L With L With L +0.0000 Minimum +0.0000 +0.0000Thread Diam., B1FIM 6 in. 6 in. 6 in. 6 in. 0.0003 Thickness 0.0003 0.0003140.2500 0.480 0.010 0.750 1.000 0.400 0.650 0.4093 0.500 0.4380 0.11865160.3125 0.600 0.011 0.875 1.125 0.417 0.667 0.5483 0.500 0.5820 0.1457380.3750 0.730 0.012 1.000 1.250
6、 0.438 0.688 0.6183 0.500 0.6550 0.17297160.4375 0.850 0.013 1.125 1.375 0.464 0.714 0.6853 0.500 0.7300 0.2100120.5000 0.980 0.014 1.250 1.500 0.481 0.731 0.8253 0.500 0.8750 0.23719160.5625 1.100 0.015 1.375 1.625 0.750 0.750 0.8953 0.500 0.9500 0.2643580.6250 1.230 0.017 1.500 1.750 0.773 0.773 1
7、.0343 0.500 1.0950 0.2914340.7500 1.470 0.020 1.750 2.000 0.800 0.800 1.2343 0.500 1.3120 0.3557GENERAL NOTE: Refer to section 4 for further information.NOTES:(1) Head acceptability shall be determined using the two rings described in Table 8. Ring B shall be placed on the screw head followed byRing
8、 T. The head is acceptable if Ring T does not contact Ring B after both rings are in place on the head.(2) The top surface of the flange shall be conical or slightly rounded (convex). Radius, R2, applies both at the corners and at the flats ofthe hexagon. The contour of edge at flange periphery, bet
9、ween the maximum flange diameter, B, max., and the minimum bearing circlediameter, B1, min., shall be optional provided that the minimum flange edge thickness, K, min., is maintained at the minimum bearingcircle diameter, B1, min.(3) LG, max. p L nom. LT; LB, min. p LG, max. Y (see para. 4.7)(4) Use
10、 Y dimensions in Table 8 for the calculation of LG, max./LB, min. (see para. 4.7) instead of following Table 12.Table 14 Dimensions of Square Lag ScrewsH S G Configuration (see para. 2.1.1) Identification (see para. 2.11.1) Screw With Reduced Diameter Body Cone PointF R E H R L E See para. 2.1.4 A S
11、ee para. 5.3 ASee para. 5.7 Gimlet Point25 approx.60 approx. 60 approx.See para. 2.6 MAp. 2 of 2 07-11-13 17:26:29 Textfile: 001109E002 Unit: UE01ASME B18.2.1-2012(Revision of ASME B18.2.1-2010)Square, Hex, HeavyHex, and Askew HeadBolts and Hex, HeavyHex, Hex Flange,Lobed Head, and LagScrews (Inch S
12、eries)AN AMERICAN NATIONAL STANDARDTwo Park Avenue New York, 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. Per
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21、 in any form,in an electronic retrieval system or otherwise,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.CONTE
22、NTSForeword ivCommittee Roster . viiCorrespondence With the B18 Committee viii1 Introduction . 12 General Data for Both Bolts and Screws. 23 Bolts 44 Screws 95 Lag Screws 19Figures1 Underhead Fillet for Long Screws . 182 Underhead Fillet for Short Screws Threaded Full Length . 183 LG, Maximum and LB
23、, Minimum for Short Screws Threaded Full Length . 19Tables1 Dimensions of Square Head Bolts . 52 Dimensions of Hex Bolts 63 Dimensions of Heavy Hex Bolts . 74 Dimensions of Askew Head Bolts . 85 Length Tolerances for Bolts . 86 Dimensions of Hex Cap Screws . 107 Dimensions of Heavy Hex Screws . 128
24、Dimensions of Hex Flange Screws 149 Dimensions of Lobed Head Screws 1610 Dimensions of Underhead Fillets 1711 LG, Maximum and LB, Minimum Limitations for Short Screws ThreadedFull Length 1812 Maximum Grip Gaging Lengths, LG, and Minimum Body Lengths, LB,for Screws Except Flange Head . 2013 Length To
25、lerances for Screws . 2314 Dimensions of Square Lag Screws . 2415 Dimensions of Hex Lag Screws . 2516 Dimensions of Lag Screw Threads 25Mandatory AppendixI Gage and Gaging Practices for External Lobed Head Drive System 27Nonmandatory AppendicesA Formulas for Bolt and Screw Head Dimensions 30B Weight
26、 in Pounds of 100 Steel Hex Cap Screws for Given Diameter/LengthCombination . 32C Countersunk Center Holes 33D Self-Locking Element and Drilled Head Guidelines 34iiiFOREWORDAmerican National Standards Committee B18 for the standardization of bolts, screws, nuts,rivets, and similar fasteners was orga
27、nized in March 1922 as Sectional Committee B18, undertheaegisoftheAmericanEngineeringStandardsCommitteeAESC,latertheAmericanStandardsAssociation (ASA), then the United States of America Standards Institute (USASI), and, as ofOctober 6, 1969, the American National Standards Institute (ANSI), with the
28、 Society ofAutomotive Engineers (SAE International) and The American Society of Mechanical Engineers(ASME) as joint sponsors. Subcommittee 2 was subsequently established and charged with theresponsibility for technical content of standards covering wrench head bolts and nuts.Subcommittee2,afterappra
29、isaloftherequirementsofindustry,developedaproposedstandardseries of bolt head and nut dimensions. This proposal was finally approved and designated atentative American Standard in February 1927.A first revision of the document was designated as an American Standard in March 1933 andwas followed by a
30、 second revision that was granted approval as an American Standard inJanuary 1941.Following reorganization of the B18 Committee in 1947, Subcommittee 2 was asked to expandthe standard on head proportions into a complete product standard. A proposal covering squareand hexagon head bolts and nuts, hex
31、agon head cap screws, and automotive hexagon head boltswas prepared and submitted to the B18 Committee in April 1950. While this draft was underconsideration, the B18 Committee received a proposal from the British Standards Institution (BSI)for unification of dimensions on products incorporating Uni
32、fied screw threads. The CommitteewelcomedtheopportunitytodiscusstheproposalsandanAmerican-British-CanadianConferencewas held in New York on June 1 and June 2, 1950.It was agreed in the conference that the essentials of unification could be accomplished byselection of mutually satisfactory across-the
33、-flats dimensions, since this would permit the use ofthe same wrenches and because other features would rarely affect interchangeability. After dueconsideration,suitableexistingacross-the-flatsdimensionswereselectedforthehexagonproductsaffected.In its meeting of October 13, 1950, Subcommittee 2 agre
34、ed to incorporate in the proposedstandard the conference recommendations on14-in. hexagon head bolts,58-in. hexagon head capscrews and automotive hexagon head bolts,516-in. and38-in. regular hexagon and square nuts,and716-in.lightandregularhexagonandsquarenuts.AtasubsequentmeetingofSubcommittee2,fur
35、ther changes were adopted in order to combine the light and regular series of nuts and tocombine the automotive hexagon head bolt, hexagon head cap screw, and regular hexagon headclose tolerance bolt.In view of the progress made in the United States and the urgency of standardization formutual defen
36、se, BSI sponsored a second conference in London in April 1951 to complete theunification of certain hexagon bolts and nuts.At a meeting on June 8, 1951, Subcommittee 2 reaffirmed its acceptance of the unified dimen-sions, which corresponded with those in the March 1951 draft, but attempted to select
37、 betternomenclature for the unified products. A final draft incorporating the nomenclature “FinishedHexagon Bolts and Nuts” and containing numerous editorial changes was submitted for letterballotinSeptember1951.FollowingapprovalbytheB18Committeeandthesponsors,theproposalwas presented to ASA for app
38、roval and designation as an American Standard. This was grantedon March 24, 1952.Recognizing the Standard was in need of additional refinements, Subcommittee 2 immediatelybegan to revise it, removing inconsistencies with respect to fillets, improving the length toleranceson heavy hexagon bolts, and
39、incorporating numerous other corrections and clarifications. Themost noteworthy editorial change was a decision to combine the coverage for hexagon cap screwsand square head set screws from the B18.2 Standard with the coverage for slotted head capscrews and slotted headless set screws from the B18.6
40、 Standard and publish them in a separateivdocument. The requirements for the unified hexagon cap screws and finished hexagon boltsbeing identical in the overlapping sizes, these data would now be available in two publications.FollowingapprovalbytheB18Committeeandsponsororganizations,theproposalwassu
41、bmittedto ASA and declared an American Standard on February 2, 1955.A revision of this document comprised of numerous editorial corrections and inclusion of anppendix for grade markings was duly approved and designated an American Standard onApril 18, 1960.At ameeting inFebruary 1960,Subcommittee 2a
42、pproved arecommendation toreduce theheadheights for heavy, heavy semifinished, and heavy finished hexagon bolts that was subsequentlyapproved by letter ballot of the B18 Committee on August 16, 1960. A proposed standard forheavy hexagon structural bolts submitted and accepted by Subcommittee 2 at it
43、s meeting onOctober 17, 1960 was approved by letter ballot of the B18 Committee on May 9, 1961. To meetthe urgent needs of the steel construction industry, it was considered necessary to publish theStandard for the structural bolts immediately. Consequently, Appendix IV to ASA B18.2-1960,containing
44、coverage for the revised heavy hexagon bolts and the new heavy hexagon structuralbolts, was released in 1962. In October of 1961, Subcommittee 2 appointed a subgroup to reviewallproductstandardsforsquareandhexagonbolts,screws,andnutsandtorecommendsimplifica-tions that would be compatible with techni
45、cal, production, and distribution advances that hadoccurred over the prior several years. The subgroup presented its recommendations at a meetingof Subcommittee 2 in October of 1962. It was agreed that the internally and externally threadedproducts should be published in separate documents as sugges
46、ted, and draft proposals for eachwere completed.Theproposedrevisionforsquareandhexboltsandscrewsincorporatedthefollowingsubgrouprecommendations: consolidation of hexagon head cap screws and finished hexagon bolts into asingle product, consolidation of heavy semifinished hexagon bolts and heavy finis
47、hed hexagonbolts into a single product, elimination of regular semifinished hexagon bolts, a new lengthtolerancing pattern for all bolts and screws, documentation of a positive identification procedurefor determining whether an externally threaded product should properly be designated a boltor a scr
48、ew, and an abbreviated and purified set of product nomenclature reflecting applicationof the identification procedure. Letter ballot of this proposal to the B18 Committee in March 1964resulted in several comments that were resolved to the satisfaction of the committee in June of1964. Following accep
49、tance by the sponsor organizations, the revision was submitted to ASAand was designated American Standard ASA B18.2.1 on September 8, 1965.Subcommittee 2 continued to further develop refinements initiated by the simplification sub-group and revisions reflecting changes in manufacturing practices and consumer requirements.This work culminated in Subcommittee acceptance of a 1970 proposal incorporating, in additionto numerous editorial changes, revisions in the following significant areas: addition of coveragefor askew head bolts and hex head lag screws,
