1、Double Coil Helical Spring Lock Washers for Wood StructuresAN AMERICAN NATIONAL STANDARDASME B18.21.3-2008Intentionally left blank ASME B18.21.3-2008Double Coil HelicalSpring Lock Washersfor Wood StructuresAN AMERICAN NATIONAL STANDARDDate of Issuance: September 19, 2008This Standard will be revised
2、 when the Society approves the issuance of a new edition. There willbe no addenda issued to this edition.ASME issues written replies to inquiries concerning interpretations of technical aspects of thisdocument. Periodically, certain actions of the ASME B18 Committee may be published as Cases.Cases a
3、nd interpretations are published on the ASME Web site under the Committee Pages athttp:/cstools.asme.org as they are issued.ASME is the registered trademark of The American Society of Mechanical Engineers.This code or standard was developed under procedures accredited as meeting the criteria for Ame
4、rican 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 for public review and comment that provides an opp
5、ortunity 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 respect to the validity of any patent rights asserted i
6、n 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 assume any such liability. Users of a code or standard are expresslyadvised that determination of the validity o
7、f 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 endorsement of this code or standard.ASME accepts respo
8、nsibility 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 an electronic retrieval system or otherwise,withou
9、t the prior written permission of the publisher.The American Society of Mechanical EngineersThree Park Avenue, New York, NY 10016-5990Copyright 2008 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.CONTENTSForeword ivCommittee Roster . vCorrespondence With the B18 Co
10、mmittee vi1 Introductory Notes 12 General Data 1Figure1 Washer Twist Test . 4Tables1 Dimensions for Double Coil Helical Spring Lock Washers for Wood Structures 32 Dimensions for Extended Travel Double Coil Helical Spring Lock Washers for WoodStructures . 43 Decarburization Limits . 44 Standard Trave
11、l Limits . 45 Extended Travel Limits 4iiiFOREWORDOn November 29, 2006, a proposed draft for a new standard to cover double coil helical springlock washers for high voltage wood structures was presented to the members present at theASME B18 Subcommittee meetings. The Committee agreed that Subcommitte
12、e 21 should proceedwith the proposed standard, eliminating the words “high voltage” so the standard could be usedby anyone looking for a lock washer for wooden structures, with the designation being B18.21.3.ASME B18.21.3-2008 was approved by B18 Subcommittee 21 and the B18 Standards Committeeon Dec
13、ember 21, 2007. This Standard was approved by the American National Standards Instituteon March 28, 2008.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
14、COMMITTEE OFFICERSD. A. Clever, ChairR. D. Strong, Vice ChairS. W. Vass, Vice ChairR. L. Crane, SecretarySTANDARDS COMMITTEE PERSONNELV. Cartina, ConsultantD. A. Clever, Deere however, theyshould not contain proprietary names or information.Requests that are not in this format may be rewritten in th
15、e appropriate format by the Committeeprior to being answered, 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 aggrie
16、ved by aninterpretation 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, whichare open to the
17、 public. Persons wishing to attend any meeting should contact the Secretary ofthe B18 Standards Committee.viASME B18.21.3-2008DOUBLE COIL HELICAL SPRING LOCK WASHERSFOR WOOD STRUCTURES1 INTRODUCTORY NOTES1.1 ScopeThis Standard covers the dimensional and physicalproperties and methods of testing for
18、double coil helicalspring lock washers for wood structures.NOTE: The word lock appearing in the name of the product inthis Standard is a generic term historically associated with theproducts identification and is not intended to imply an indefinitepermanency of fixity in attachments where the fasten
19、ers are used.1.2 Comparison to ISO StandardsNo comparable ISO standards exist for this part.1.3 DimensionsAll dimensions in this Standard are in inches andapply to unplated or uncoated product.1.4 OptionsOptions, if required, shall be agreed upon by the pur-chaser and the manufacturer or distributor
20、.1.5 TerminologyFor definitions of terminology not specifically definedin this Standard, refer to ASME B18.12.1.6 Referenced StandardsUnless otherwise specified, the standards referencedshall be the most recent at the time of the orderplacement.ASME B18.12, Glossary of Terms for MechanicalFastenersA
21、SME B18.18.1, Inspection and Quality Assurance forGeneral Purpose FastenersASME B18.21.1, Lock Washers (Inch Series)ASME B18.24, Part Identifying Number (PIN) CodeSystem Standard for B18 Fastener ProductsPublisher: The American Society of MechanicalEngineers (ASME), Three Park Avenue, New York,NY 10
22、016-5990; Order Department: 22 Law Drive, P.O.Box 2300, Fairfield, NJ 07007-2300ASTM B 117, Standard Practice for Operating Salt Spray(Fog) ApparatusASTM E 140, Standard Hardness Conversion Tables ofMetals (Relationship Among Brinell Hardness,1Vickers Hardness, Rockwell Hardness, RockwellSuperficial
23、 Hardness, Knoop Hardness, andScleroscope Hardness)Publisher: ASTM International (ASTM), 100 Barr HarborDrive, P.O. Box C700, West Conshohocken, PA19428-2959SAE J403, Chemical Composition of SAE Carbon SteelsSAE J411, Carbon and Alloy SteelsSAE J419, Methods of Measuring DecarburizationPublisher: Th
24、e Society of Automotive Engineers (SAE),400 Commonwealth Drive, Warrendale, PA 15096-00011.7 Related StandardsRelated lock washers and tests are included inASME B18.21.1.1.8 DesignationNominal washer sizes are intended for use with com-parable nominal screw, bolt, and/or nut sizes. Fastenersconformi
25、ng to this Standard shall be designated by thefollowing data and sequence:(a) product name(b) ASME document number(c) nominal sizeEXAMPLE: Double coil helical spring lock washers for woodstructures, ASME B18.21.3,58in.1.9 Part Identifying NumberFor a part identifying number, refer to ASME B18.24.2 G
26、ENERAL DATA2.1 ApplicationThe double coil helical spring lock washers for woodstructures covered in this Standard are intended to beused with a curved flat washer or the standard hardwarepractice of the user against the wood. While not essen-tial, it is a good practice to use a standard round washer
27、between the double coil helical spring lock washer andthe nut, then tighten the nut in accordance with theusers standard practice, and back off the nut14(90 deg)turn. This is important to maintain an acceptable pres-sure on the hardware and the wood fibers which mayshrink or swell during varying wea
28、ther conditions.ASME B18.21.3-2008Although these washers were designed specifically foruse on bolts in wooden assemblies (poles, crossarms,etc.), they can also be used for general applicationswhere a heavy duty double coil washer is needed.2.2 DimensionsThe dimensions of standard and extended travel
29、 dou-ble coil helical spring lock washers for wood structuresare specified in Tables 1 and 2 and are before coating.Selections should be made from standard or extendedtravel series in Tables 1 and 2, respectively, to suit designrequirements.2.3 Material and Hardness2.3.1 Material Composition. Washer
30、s shall be madefrom material meeting the chemical compositionrequirements of the following standards:(a) up to and including34in. carbon steel SAE J4031055-1065 (UNS G10550-G10650)(b)78in. and above boron steel SAE J411 10B55-10B652.3.2 Hardness. All washer section hardnessrequirements are 38 HRC to
31、 46 HRC, 372 HV to 458 HV.To prepare washers for checking the material hardness,cut washer approximately in half so only one coil isused. Cold (water) grind or file both sides sufficientlyflat and parallel to ensure a correct reading. If applicable,be sure to remove the decarburized and coated surfa
32、ce.During this operation, care shall be exercised to preventthe surface temperature from exceeding 250F. Refer toASTM E 140 for hardness conversion.2.3.3 Decarburization. Carbon steel and boron steelshall meet the limits for decarburization shown inTable 3. The method for testing limits shall confor
33、m toSAE J419.2.4 Washer SectionThe corners at the inner and outer peripheries of thewashers shall be slightly rounded. The section of thefinished washer shall be slightly trapezoidal with thick-ness at the inner periphery greater than the thicknessat the outer periphery by a minimum of 0.0005 in. to
34、 amaximum of 0.001 in. per 0.0156 in. of the section width.The minimum section thickness specified in the dimen-sional tables represents the nominal mean thickness, T,of the trapezoid. The tolerance on the nominal meanthickness of the trapezoid shall be subject to thefollowing:Size Tolerance38to580.
35、01534to 1 0.02522.5 CoilingWashers shall be coiled so that the gap between coilsshall be such as to prevent washers from linking. Thesevered ends of the washers are to be cut so that theends are less then two full coils as shown in Tables 1and 2, dimension C.2.6 WorkmanshipThe flat surfaces (faces)
36、of the double coil helicalspring lock washers shall be free from such surfaceimperfections as knurling, serrations, die marks, deepscratches, loose scale, burrs, or other irregularities thatwould affect serviceability. Moderate feed roll marksshall be permissible on the outer periphery.2.7 GrindingT
37、he face on both severed ends of the washer shall beground prior to heat treating to provide a flat surfaceon each side as shown in Tables 1 and 2, dimensions Dand F.2.8 FinishAll washers shall be mechanically coated and shallmeet a minimum of 1,500 hr to red rust when tested inaccordance with ASTM B
38、 117.2.9 Twist TestTo prepare washers for twist testing, cut the washerapproximately in half so only one coil is used. Thewasher shall be gripped in vice jaws. The ends of thewasher shall be free, and the axis passing through theslot shall be parallel to and slightly above the top of thevice so that
39、 less then 50% of the washer is gripped. A90 deg maximum segment of the free end of the washershall be gripped in wrench jaws so that at least 25% ofthe washer is exposed when twisting, as shown in Fig. 1.The edges of the wrench jaws shall be in a plane parallelto the vice. Twisting the wrench incre
40、asing the freeheight of the washer section between 85 deg and 95 degshall show no signs of fracture.2.10 TravelTravel shall be measured by placing the washerbetween hardened steel plates, one of which is move-able, until the washer is being touched by both plates.From this point, measure the distanc
41、e required to com-pletely close the washer. Minimum travel requirementsare shown in Tables 4 and 5.2.11 Inspection and Quality AssuranceUnless otherwise specified, products shall be fur-nished in accordance with ASME B18.18.1.ASME B18.21.3-2008Table 1 Dimensions for Double Coil Helical Spring Lock W
42、ashers for Wood StructuresFEDBACWTto tiMinimumMaximum Maximum MeanInside Diameter, Cutoff Angle,Nominal Outside Gap Section MinimumAC, degWasher Diameter, Minimum Minimum Between Thickness, GroundSize Min. Max. B Min. Max. Height, D Width, W Coils, ETNote (1) Face, F380.385 0.408 0.814 30 35 0.530 0
43、.196 0.145 0.156 0.078120.510 0.535 1.035 30 35 0.530 0.243 0.145 0.156 0.078580.635 0.660 1.284 30 35 0.785 0.302 0.220 0.234 0.117340.760 0.791 1.415 30 35 0.785 0.302 0.220 0.234 0.117780.885 0.915 1.808 30 35 0.860 0.437 0.229 0.250 0.1251 1.010 1.040 1.928 30 35 0.860 0.437 0.229 0.250 0.125NOT
44、E:(1) T p (ti+ to)/2.3ASME B18.21.3-2008Table 2 Dimensions for Extended Travel Double Coil Helical Spring Lock Washers for Wood StructuresFEDBACWTto tiMinimumMaximum Maximum MeanInside Diameter, Cutoff Angle,Nominal Outside Gap Section MinimumAC, degWasher Diameter, Minimum Minimum Between Thickness
45、, GroundSize Min. Max. B Min. Max. Height, D Width, W Coils, ETNote (1) Face, F580.635 0.660 1.284 30 35 1.000 0.302 0.255 0.285 0.142340.773 0.791 1.415 30 35 1.000 0.302 0.255 0.285 0.142NOTE:(1) T p (ti+ to)/2.Table 3 Decarburization LimitsMaximum TotalMaximum Affected DepthDiameters of Round Dep
46、th of (Free FerriteWire or Sections of Free Plus PartialEquivalent Area Ferrite Decarburization)Up to 0.140, incl. 0.002 0.006Over 0.140 to 0.250, incl. 0.003 0.008Over 0.250 to 0.375, incl. 0.004 0.010Over 0.375 to 0.500, incl. 0.006 0.015Fig. 1 Washer Twist TestDirectionof rotation4Table 4 Standar
47、d Travel LimitsSize Minimum380.130120.130580.200340.200780.2091 0.209Table 5 Extended Travel LimitsSize Minimum580.250340.250B18 AMERICAN NATIONAL STANDARDS FOR BOLTS, NUTS, RIVETS, SCREWS,WASHERS, AND SIMILAR FASTENERSSmall Solid Rivets B18.1.1-1972 (R2006)Large Rivets .B18.1.2-1972 (R2006)Metric S
48、mall Solid Rivets .B18.1.3M-1983 (R2006)Square and Hex Bolts and Screws (Inch Series) B18.2.1-1996 (R2005)Square and Hex Nuts (Inch Series) B18.2.2-1987 (R2005)Metric Hex Cap Screws .B18.2.3.1M-1999 (R2005)Metric Formed Hex Screws .B18.2.3.2M-2005Metric Heavy Hex Screws .B18.2.3.3M-1979 (R2001)Metri
49、c Hex Flange Screws .B18.2.3.4M-2001 (R2006)Metric Hex Bolts B18.2.3.5M-1979 (R2006)Metric Heavy Hex Bolts.B18.2.3.6M-1979 (R2006)Metric Heavy Hex Structural Bolts B18.2.3.7M-1979 (R2006)Metric Hex Lag Screws .B18.2.3.8M-1981 (R2005)Metric Heavy Hex Flange Screws .B18.2.3.9M-2001 (R2006)Square Head Bolts (Metric Series) .B18.2.3.10M-1996 (R2003)Metric Hex Nuts, Style 1 B18.2.4.1M-2002 (R2007)Metric Hex Nuts, Style 2 .B18.2.4.2M-2005Metric Slotted Hex Nuts B18.2.4.3M-1979 (R2006)Metric Hex Flange Nuts .B18.2.4.4M-1982 (R2005)Metric Hex Jam Nuts .B18.2.4.5M-1
