1、AN AMERICAN NATIONAL STANDARD ASME B18.16.6-2014(Revision of ASME B18.16.6-2008)Prevailing Torque Locknuts(Inch Series)ASME B18.16.6-2014(Revision of ASME B18.16.6-2008)PrevailingTorque Locknuts(Inch Series)AN AMERICAN NATIONAL STANDARDTwo Park Avenue New York, NY 10016 USADate of Issuance: April 30
2、, 2014This 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. Interpretations are published on the Committee Web page and undergo.asme.org/InterpsDatabase. Periodic
3、ally certain actions of the ASME B18 Committee may bepublished as Cases. Cases are published on the ASME Web site under the B18 Committee Page atgo.asme.org/B18committee as they are issued.Errata to codes and standards may be posted on the ASME Web site under the Committee Pages toprovide correction
4、s to incorrectly published items, or to correct typographical or grammatical errorsin codes and standards. Such errata shall be used on the date posted.The B18 Committee Page can be found at go.asme.org/B18committee. There is an option availableto automatically receive an e-mail notification when er
5、rata are posted to a particular code or standard.This option can be found on the appropriate Committee Page after selecting “Errata” in the “PublicationInformation” section.ASME is the registered trademark of The American Society of Mechanical Engineers.This code or standard was developed under proc
6、edures accredited as meeting the criteria for American NationalStandards. The Standards Committee that approved the code or standard was balanced to assure that individuals fromcompetent and concerned interests have had an opportunity to participate. The proposed code or standard was madeavailable f
7、or public review and comment that provides an opportunity for additional public input from industry, academia,regulatory agencies, and the public-at-large.ASME does not “approve,” “rate,” or “endorse” any item, construction, proprietary device, or activity.ASME does not take any position with respec
8、t to the validity of any patent rights asserted in connection with anyitems mentioned in this document, and does not undertake to insure anyone utilizing a standard against liability forinfringement of any applicable letters patent, nor assumes any such liability. Users of a code or standard are exp
9、resslyadvised that determination of the validity of any such patent rights, and the risk of infringement of such rights, isentirely their own responsibility.Participation by federal agency representative(s) or person(s) affiliated with industry is not to be interpreted asgovernment or industry endor
10、sement of this code or standard.ASME accepts responsibility for only those interpretations of this document issued in accordance with the establishedASME procedures and policies, which precludes the issuance of interpretations by individuals.No part of this document may be reproduced in any form,in
11、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 2014 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.CONTENTSForeword ivCo
12、mmittee Roster . vCorrespondence With the B18 Committee vi1 Introduction . 12 Reference Standards . 13 Terminology . 14 Dimensions 15 Nut Designs and Property Grades . 16 Corner Fill . 27 Chamfers and Bearing Circles. 28 Countersinks 29 Threads . 210 Material, Mechanical, and Performance Properties
13、. 1111 Test Methods 1112 Grades and Manufacturing Marking . 1513 Quality Assurance 1514 Workmanship 1515 Designation . 15Tables1 Chemical Composition Requirements . 22 Hardness Requirements . 23 Style NE Nylon Insert Locknut Dimensions . 34 Style NTE Nylon Insert Locknut Dimensions 45 Style NU Nylon
14、 Insert Locknut Dimensions . 56 Style NTU Nylon Insert Locknut Dimensions 67 Style NM Nylon Insert Locknut Dimensions . 78 Style NTM Nylon Insert Locknut Dimensions . 79 Dimensions of Nylon Insert Hex Flange Nuts . 810 Dimensions of Prevailing Torque All-Metal Type Hex Nuts 911 Dimensions of Prevail
15、ing Torque All-Metal Type Hex Flange Nuts . 1012 Proof Loads, Clamp Loads, and Prevailing Torques for Coarse Thread Locknuts 1213 Proof Loads, Clamp Loads, and Prevailing Torques for Fine Thread Locknuts 1314 Proof Loads, Clamp Loads, and Prevailing Torques for UN8 Series ThreadLocknuts . 13iiiFOREW
16、ORDASME B18.16.6-2008 was balloted and approved by the B18 Standards Committee andB18 Subcommittee 16 on April 29, 2008. The proposal was submitted to the American NationalStandards Institute and designated as an American National Standard on August 25, 2008.At the B18 meeting in the Fall of 2011, S
17、ubcommittee 16 decided to expand this Standardto include all styles of locking nuts. B18.16.6 will now contain dimensional and performancerequirements for nonmetallic insert and all-metal locking nuts in a variety of grades. This Standardis intended to replace IFI-100/107 which the Industrial Fasten
18、ers Institute has agreed to withdrawafter the publication of this Standard.This revision was approved as an American National Standard on March 12, 2014.Suggestions for improvement of this Standard are welcome. They should be sent to Secretary,B18 Committee, The American Society of Mechanical Engine
19、ers, Two Park Avenue, New York,NY 10016-5990.ivASME B18 COMMITTEEStandardization 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.)STANDARDS COMMITTEE OFFICERSJ. Greenslade, ChairD. S. George, Vice Cha
20、irW. H. King, Vice ChairC. J. Gomez, SecretarySTANDARDS COMMITTEE PERSONNELV. Cartina, Nylok, LLCD. A. Clever, Contributing Member, ConsultantA. P. Cockman, Ford Motor Co.C. A. D. de la Garza, TSP, Inc.D. S. George, Ramco SpecialtiesC. J. Gomez, The American Society of Mechanical EngineersJ. Greensl
21、ade, Industrial Fasteners InstituteJ. J. Grey, Contributing Member, Fastener Consulting Services, Inc.A. Herskovitz, Contributing Member, ConsultantJ. Hubbard, Leland-Powell Fasteners, Inc.J. C. Jennings, Contributing Member, Naval Surface Warfare CenterW. H. King, Fastenal Co.SUBCOMMITTEE 16 NUTSV.
22、 Cartina, Chair, Nylok, LLCD. S. George, Vice Chair, Ramco SpecialtiesT. Anderson, Bay BoltL. C. Borowski, Greenslade however, they shouldnot contain proprietary names or information.Requests that are not in this format may be rewritten in the appropriate format by the Committeeprior to being answer
23、ed, which may inadvertently change the intent of the original request.ASME procedures provide for reconsideration of any interpretation when or if additionalinformation that might affect an interpretation is available. Further, persons aggrieved by aninterpretation may appeal to the cognizant ASME C
24、ommittee 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 meetingsand/or telephone conferences that are open to the public. Persons wishing to att
25、end any meetingand/or telephone conference should contact the Secretary of the B18 Standards Committee. FutureCommittee meeting dates and locations can be found on the Committee Page atgo.asme.org/B18committee.viASME B18.16.6-2014PREVAILING TORQUE LOCKNUTS(INCH SERIES)1 INTRODUCTION1.1 ScopeThis Sta
26、ndard covers the complete general, dimen-sional, mechanical, and performance requirements(proof load, prevailing torque, and torque-tension) forcarbon steel, inch series nylon insert locknuts of gradesN2, N5, and N8 in styles NE (14in. to 112in.),NTE (14in. to 112in.), NU (14in. to 3 in.), NTU(14in.
27、 to 3 in.), NM (#2 to #12), NTM (#2 to #12), andhex flange (14in. to34in.). This Standard also includesall-metal hex (#4 to 112in.) and hex flange (14in. to34in.)locking nuts of grades A, B, C, F, and G. These nutdesigns are designated as American National Standards.1.2 Comparison to ISO StandardsTh
28、ere is no ISO inch standard for these products.2 REFERENCE STANDARDSThe following is a list of publications referenced inthis Standard. Unless otherwise specified, the referencestandard(s) shall be the most recent issue at the time oforder placement.ASME B1.1, Unified Inch Screw ThreadsASME B1.3, Sc
29、rew Thread Gaging Systems forAcceptability: Inch and Metric Screw Threads (UN,UNR, UNJ, M, and MJ)ASME B1.15, Unified Inch Screw Threads (UNJ ThreadForm)ASME B18.2.1, Square, Hex, Heavy Hex, and AskewHead Bolts and Hex, Heavy Hex, Hex Flange, LobedHead, and Lag Screws (Inch Series)ASME B18.12, Gloss
30、ary of Terms for MechanicalFastenersASME B18.18, Quality Assurance for FastenersASME B18.21.1, Washers: Helical Spring-Lock, ToothLock and Plain WashersPublisher: The American Society of MechanicalEngineers (ASME), Two Park Avenue, New York,NY 10016-5990; Order Department: 22 Law Drive, P.O.Box 2900
31、, Fairfield, NJ 07007-2900 (www.asme.org)ASTM F436, Hardened Steel Washers1ASTM F606, Test Methods for Determining theMechanical Properties of Externally and InternallyThreaded Fasteners, Washers, and RivetsASTM F788, Surface Discontinuities of Bolts, Screws,and Studs, Inch and Metric SeriesASTM F81
32、2, Surface Discontinuities of Nuts (Inch Series)ASTM F1137, Standard Specification for Phosphate/OilCorrosion Protective Coatings for FastenersASTM F1470, Standard Practice for Fastener Samplingfor Specified Mechanical Properties and PerformanceInspectionASTM F1941, Electrodeposited Coatings on Thre
33、adedFasteners Unified Inch Screw Threads (UN/UNR)Publisher: ASTM International, 100 Barr Harbor Drive,P.O. Box C700, West Conshohocken, PA 19428-2959(www.astm.org)IFI-101, Torque-Tension Requirements for Prevailing-Torque Type Steel Hex and Hex Flange NutsPublisher: Industrial Fasteners Institute (I
34、FI),6363 Oak Tree Blvd., Independence, OH 44131(www.indfast.org)SAE J409, Product Analysis Permissible Variationsfrom Specified Chemical Analysis of a Heat or Castof SteelPublisher: SAE International, 400 Commonwealth Drive,Warrendale, PA 15096-0001 (www.sae.org)3 TERMINOLOGYFor definitions of terms
35、 relating to fasteners or compo-nent features thereof used in this Standard, refer toASME B18.12.4 DIMENSIONSUnless otherwise specified, all dimensions in thisStandard are inches and shall be as specified in the tablesand sections 6 through 9. All dimensions apply beforecoating.5 NUT DESIGNS AND PRO
36、PERTY GRADES5.1 Nylon Insert LocknutsNylon insert locknuts are two-piece construction hexnuts and hex flange nuts that derive their prevailingASME B18.16.6-2014Table 1 Chemical Composition RequirementsC, Mn, P, S,Nut Grade Max. Min. Max. Max.N2, A 0.47 . . . 0.12 0.15Note (1) Note (2)N5, B, F 0.55 0
37、.30 0.05 0.15Notes (3), (4) Notes (2), (4)N8, C, G 0.55 0.30 0.04 0.05Note (5)GENERAL NOTE: All values are for ladle analysis (percent by weight)and are subject to standard variations for check analysis as given inSAE J409.NOTES:(1) Resulfurized and rephosphorized material is not subject torejection
38、 based on check analysis for sulfur.(2) If agreed between purchaser and producer, sulfur content maybe 0.23 max.(3) Phosphorus content may be 0.13 max. for acid bessemer steelonly.(4) If agreed between purchaser and producer, sulfur content maybe 0.35 max. and phosphorus content may be 0.12 max., pr
39、o-vided that manganese content is 0.70 min.(5) If agreed between purchaser and producer, sulfur content maybe 0.33 max., provided that manganese content is 1.35 min.torque characteristics from a full ring of nylon material,located and retained in the nut under its top surface.These are designated in
40、 Table 1 as property grades N2,N5, and N8 with hardness requirements in Table 2. Theconfiguration styles are NE (Table 3), NTE (Table 4), NU(Table 5), NTU (Table 6), NM (Table 7), NTM (Table 8),and hex flange (Table 9).5.2 All-Metal LocknutsAll-metal locknuts are one-piece construction hex andhex fl
41、ange nuts that derive their prevailing torque per-formance from controlled distortion of the nut threadsand/or body. Hex locknuts are designated as grades A,B, and C. The dimensions are located in Table 10. Hexflange locknuts are designated as grades F and G. Thedimensions are in Table 11. Table 1 i
42、dentifies the materialrequirements for the various grades and Table 2 identi-fies sizes and hardness requirements for the variousgrades.6 CORNER FILLA rounding or lack of fill at the location where the hexcorners intersect with the chamfer shall be permissible,provided the width across corners is wi
43、thin specifiedlimits.2Table 2 Hardness RequirementsNut Grade Locknut SizeNote (1) Note (2) Rockwell HardnessN2, N5, A, B, and F14112C28, max.N8, C, and G1458C24C32341 C26C34118112C26C36NOTES:(1) For grade N2 sizes over 112, the minimum hardness shall beHRB 68.(2) For values on sizes not listed in Ta
44、ble 10, agreement shall bereached between purchaser and supplier.7 CHAMFERS AND BEARING CIRCLES7.1 Chamfer Length on Bearing Side of NutsThe length of chamfer at hex corners shall be from5% to 15% of the nominal thread diameter. The surfaceof the chamfer may be convex or rounded.7.2 Bearing Surface
45、DiameterThe diameter of bearing circle on chamfered nuts andwasher-faced nuts shall be within the limits of the maxi-mum width across flats and 95% of the minimum widthacross flats.8 COUNTERSINKSUnless otherwise specified in this Standard, tappedholes shall be countersunk on the bearing faces. Thema
46、ximum countersink diameter shall be the nominalthread diameter plus 0.030 in. for38in. nominal sizenuts and smaller, and 1.08 times the nominal threaddiameter for nuts larger than38in. No part of thethreaded portion shall project beyond the bearingsurface.9 THREADSThreads shall be unified thread for
47、m coarse, fine, or8 thread series (UNC, UNF, or UN8) Class 2B in accor-dance with ASME B1.1 or UNJ thread form (UNJC,UNJF, or UNJ8 series) either Class 2B or 3B in accordancewith ASME B1.15 provided all performance require-ments of the final parts are in compliance.Inspection shall be in accordance
48、with System 21 ofASME B1.3. Inspection shall be conducted prior to nutdeformation or nylon ring captivation.After deformation or nylon captivation, the GOthreaded plug gage must enter38in. and smaller nutsat least one-half turn, and for716in. nuts and above onefull turn from the bearing surface side
49、 of the nut.ASME B18.16.6-2014Table 3 Style NE Nylon Insert Locknut DimensionsABCDMaximum RunoutDesignation Width AcrossMinimum Minimum of BearingFlats, A Thickness, CNominal Width Across Hex Surface WithSize Diameter Max. Min. Corners, B Max. Min. Height, D Thread P.D. FIM140.2500 0.439 0.430 0.482 0.328 0.298 0.225 0.0105160.3125 0.502 0.489 0.552 0.359 0.329 0.250 0.011380.3750 0.564 0.551 0.622 0.468 0.438 0.335 0.0127160.4375 0.627 0.616 0.698 0.468 0.438 0.324 0.013120.5000 0.752 0.736 0.837 0.609 0.579 0.464 0.0149160.5625 0.
