1、Designation: F2329 11Standard Specification forZinc Coating, Hot-Dip, Requirements for Application toCarbon and Alloy Steel Bolts, Screws, Washers, Nuts, andSpecial Threaded Fasteners1This standard is issued under the fixed designation F2329; the number immediately following the designation indicate
2、s the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers the requirements for
3、 hot-dipzinc coating applied to carbon steel and alloy steel bolts,screws, washers, nuts, and special threaded fasteners appliedby the hot-dip coating process. Nails and rivets are notincluded in this specification.1.2 It is intended to be applicable to fasteners that arecentrifuged or otherwise han
4、dled to remove excess galvanizingbath metal (free zinc).1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues
5、 from the two systems may result in non-conformancewith the standard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the
6、applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A153/A153M Specification for Zinc Coating (Hot-Dip) onIron and Steel HardwareA563 Specification for Carbon and Alloy Steel NutsA563M Specification for Carbon and Alloy Steel Nuts(Metric)B487 Test Method
7、for Measurement of Metal and OxideCoating Thickness by Microscopical Examination of CrossSectionE376 Practice for Measuring Coating Thickness byMagnetic-Field or Eddy-Current (Electromagnetic) TestingMethodsF606 Test Methods for Determining the Mechanical Prop-erties of Externally and Internally Thr
8、eaded Fasteners,Washers, Direct Tension Indicators, and RivetsF606M Test Methods for Determining the MechanicalProperties of Externally and Internally Threaded Fasteners,Washers, and Rivets (Metric)F1470 Practice for Fastener Sampling for Specified Me-chanical Properties and Performance InspectionF1
9、789 Terminology for F16 Mechanical Fasteners3. Terminology3.1 Terms used in this specification are defined in Termi-nology F1789 unless otherwise defined in this specification.3.1.1 batch lotquantity of identical parts cleaned, pickled,fluxed, and galvanized together at one time in a galvanizingbask
10、et.3.1.2 galvanizinghot-dip zinc coating.3.1.3 high temperature galvanizinggalvanizing processcarried out in a ceramic vessel (kettle) at an approximatetemperature ranging between 990F and 1040F 530C and560C.3.1.4 hot-dip zinc coating of mechanical fastenersprocesswhereby fasteners are zinc coated b
11、y immersion in a bath ofmolten zinc, resulting in the formation of the iron/zinc alloycoating and a zinc coating at the surface of the fastener. Thisprocess involves the removal of excess zinc by spinning theparts in a centrifuge, or brushing the threaded portion, orhandling otherwise to remove the
12、excess zinc.3.1.5 production lotbatches of parts originating from thesame manufacturing lot, processed continuously through clean-ing, pickling, fluxing, dipping in molten zinc and spun in acentrifuge, or other means, without any significant change intime, temperature, and concentration of the const
13、ituents of theprocess.3.1.6 stress reliefprocess of heating parts for a definitetime at a given temperature in order to relieve stress induced bywork hardening.1This specification is under the jurisdiction of ASTM Committee F16 onFasteners and is the direct responsibility of Subcommittee F16.03 on C
14、oatings onFasteners.Current edition approved Dec. 1, 2011. Published December 2011. Originallyapproved in 2005. Last previous edition approved in 2011 as F2329-05(2011). DOI:10.1520/F2329-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serv
15、iceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Ordering Information4.1 Orders for zinc coating of f
16、asteners to this specificationshall include the following:4.1.1 Name of product (that is bolt, stud, nut, washers, orother);4.1.2 ASTM designation and year of issue, including fas-tener specification number;4.1.3 Hydrogen embrittlement relief treatment, as requiredby the purchaser (see, 7.2.3);4.1.4
17、 Quantity of fasteners to be hot-dip zinc coated;4.1.5 Stress relief or tempering temperature to which thefasteners where subjected, if applicable;4.1.6 Secondary processing such as chromating, phosphat-ing, or lubrication, if applicable;4.1.7 Average galvanizing temperature to which fastenerswill b
18、e subjected, if required by the purchaser (see 7.2.2);4.1.8 Specify baking if required (see 7.2.3); and4.1.9 Certification, if required (see 14.1).5. Materials and Manufacture5.1 Condition of the As-Received FastenersThe fastenersas received by the galvanizer shall be free from contaminantsthat are
19、not readily removed in the cleaning process and wouldadversely affect the galvanizing.5.2 ProcessUnless otherwise covered in this specifica-tion, all processing parameters shall be in accordance with therequirements of Specification A153/A153M.5.2.1 Process ControlGalvanized fasteners subjected to a
20、process control plan based upon batch lot level shall complywith the batch lot sampling plan in Table 1, and the samplingplan for production lot (prevention process) as determined in10.2.2 shall be applied.5.3 Spinning and Quenching:5.3.1 Parts shall be spun immediately following removalfrom the gal
21、vanizing bath and quenched in water. In addition,small parts shall be air cooled, as needed, in order to preventthe formation of zinc oxide.5.3.2 Parts, which cannot be spun shall be brushed orhandled otherwise to remove the excess zinc.5.4 Alteration of Threaded Fasteners:5.4.1 Fasteners that have
22、been hot-dip galvanized shall notbe further altered (such as subjected to a cutting, rolling, orfinishing-tool operation) by the galvanizer unless specificallyauthorized in writing by the purchaser.5.4.2 Hot-dip galvanizing of externally threaded fastenersshall meet the thread fitting requirements o
23、f the specifiedproduct standard or specific allowance as determined by thecustomer.NOTE 1The scope of this specification does not cover the require-ments regarding the overtapping of galvanized nuts. These requirementsare established by the applicable product standard, such as SpecificationA563, Spe
24、cification A563M (or others), or in writing by the purchaser, ifneeded.5.5 Secondary Processing:5.5.1 When requested by the purchaser, treatments such aschromating or phosphating shall be applied to reduce thepossibility of wet storage staining (white corrosion) or to assistsubsequent painting.5.5.2
25、 When specified on the purchase order, the nuts, bolts,or screws shall be lubricated to enhance assembly.6. Chemical Composition of Zinc6.1 Unless otherwise specified in the product standard, thezinc used for the coating shall conform to the requirements ofthe section on Zinc of Specification A153/A
26、153M.7. Safeguards Against Alteration of Fasteners MechanicalProperties7.1 Stress ReliefFasteners subjected to severe work hard-ening shall be stress-relieved by the fastener manufacturerprior to hot-dip zinc coating (galvanizing).7.2 Hot-Dip Zinc Coating:7.2.1 Effect of Temperature on Mechanical Pr
27、operties:7.2.1.1 Galvanizing carried out at a temperature above800F 425C can adversely affect the final mechanicalproperties of the fasteners. Therefore, the supplier of thefasteners submitting the product to the galvanizer shall beaware of the tempering temperature of the fasteners relative tothe t
28、emperature of the galvanizing bath and the potential effectit may have on the product. When requested by the purchaser,the average galvanizing temperature that the fasteners will besubjected to shall be furnished.7.2.1.2 Unless otherwise required by the product standard orby the purchaser, testing f
29、or mechanical properties is notnecessary if the galvanizing process is carried out at a lowertemperature than the stress relief or tempering temperature ofthe fasteners. If the galvanizing process is carried out at ahigher temperature than the stress relief or the temperingtemperature of the fastene
30、rs, than the purchaser shall makeprovision for mechanical testing.7.2.1.3 Threaded fasteners made from carbon or alloy steelheat treated to a minimum specified hardness of 40 HRC, orcase hardened steel fasteners shall not be hot-dip zinc coated.7.2.2 Effect of Hydrogen on the Mechanical Properties a
31、fterGalvanizing Hydrogen has the potential of being introducedinto the steel during acid pickling, prior to hot-dip galvanizing.For high strength fasteners (having a specified minimumproduct hardness of 33 HRC), there is a risk of internalhydrogen embrittlement. If required by the product standard o
32、rby the purchaser, mechanical descaling (with or without flashpickling) or baking shall be conducted to reduce the risk ofinternal hydrogen embrittlement. Baking shall be conductedafter pickling and prior to hot-dip galvanizing.TABLE 1 Process Control of Batch LotASampling PlanSample SizeBBatch Lot
33、Size Average CoatingThicknessCAdhesion AppearanceD5to25 1 1 126 to 50 1 1 251 to 150 2 1 2151 and over 2 2 2AThe acceptance criterion in all cases is zero defects.BThe sample size is the number of specimen(s) required to be tested/inspectedto the applicable criteria.CFrequency of coating thickness m
34、easurements: one set of specimen(s) forevery five batch lots. For test method, see 11.1.DVisual inspection for conformance.F2329 1127.2.3 Effect of the Galvanizing TemperatureExternallythreaded ferrous fasteners over 1.00 in. M24 diameter with aspecified minimum hardness of HRC 33 and higher shall n
35、ot behot-dip zinc coated at high temperature (see definition in 3.1.3)in order to avoid microcracks.8. Coating and Dimensional Requirements8.1 Coating ThicknessThe zinc coating thickness shallmeet the requirements of Table 2.8.2 DimensionThe dimensional characteristics of the fas-teners shall be in
36、accordance with the requirements of thepurchaser, when specified in the order. The purchaser shallensure that the effect of the heat generated by the galvanizingprocess is compatible with the fastener regarding the finaldimensional characteristics of the parts. Furthermore, thegalvanizer shall not b
37、e held responsible for any unanticipateddistortion of parts. In addition, the purchaser shall providefasteners having sufficient dimensional allowance to accom-modate the zinc thickness deposition, as required in 8.1.8.3 Adhesion of Zinc CoatingThe zinc coating shalladhere tenaciously to the surface
38、 of the base metal. The methodfor testing the condition of adherence is specified in 11.5.9. Workmanship, Finish, and Appearance9.1 Appearance of Zinc Coating:9.1.1 After hot-dip galvanizing, the fasteners shall meet therequirements of the section on Workmanship, Finish, andAppearance of Specificati
39、on A153/A153M. Galvanized wash-ers shall not be bonded to each other (See Note 2). Parts maybe dull due to the presence of silicon in the steel. The dullappearance shall not be cause for rejection.NOTE 2Hot-dip washers tend to bond to each other. Suitable accep-tance criteria shall be agreed between
40、 the purchaser and the galvanizerbefore placing the order. Unless otherwise agreed to in the purchase order,delivered galvanized washers shall not be bonded to each other.9.1.2 The test method shall be in accordance with 11.3.9.2 Smoothness of Zinc Coating:9.2.1 The zinc coating shall be smooth and
41、reasonablyuniform in thickness, as defined in the section on Workman-ship, Finish, and Appearance of Specification A153/A153M.Smoothness of a surface is a relative term. Minor roughnessthat does not impair the intended use of the part, or roughnessthat is related to the uncoated surface condition of
42、 the part,shall not constitute grounds for rejection of the parts.9.2.2 The test method shall be in accordance with 11.3.10. Sampling10.1 Test specimens shall be selected at random from eachproduction lot or batch lot, when applicable.10.2 Selection of the Sampling PlanProduction LotTwosampling plan
43、s are proposed, one based on detection processand one based on prevention process as defined in TerminologyF1789. The selection of the sampling plan shall be in accor-dance with Guide F1470.10.2.1 Production LotDetection ProcessSampling forcoating thickness and for visual appearance shall be conduct
44、edin accordance with Table 1, Sample Level A, and Table 3,Sample Size A, of Guide F1470. Sampling for adhesion testshall be in accordance with Table 1, Sample Level C, and Table3, Sample Size C, of Guide F1470.10.2.2 Production LotPrevention ProcessSampling forcoating thickness and for visual appear
45、ance shall be conductedin accordance with Table 2, Sample Level B, and Table 3Sample Size B, of Guide F1470. Sampling for adhesion testshall be in accordance with Table 2, Sample Level D, and Table3, Sample Size D, of Guide F1470.11. Test Methods11.1 Tests shall be made to ensure that the zinc coati
46、ng isbeing furnished in accordance with this specification and asspecified for the following:11.2 Coating Thickness:11.2.1 Average Coating Thickness on an Individual Speci-men:11.2.1.1 To calculate the average coating thickness of onespecimen, a minimum of five readings shall be taken. In casethe ge
47、ometry of the specimen does not permit five readings,five test specimens shall be used to establish the averagereading.11.2.1.2 The determination of the coating thickness shall bemade on a portion of the fastener that does not include anythreads in accordance with Practice E376.TABLE 2 Zinc Coating
48、ThicknessMinimum Thickness on SurfaceDimensionA,BAverage Thickness of AllSpecimens Tested(Production Lot)C,BAverage Thickness of AllSpecimens Tested(Batch Lot)D,BAverage Thickness ofIndividual SpecimenBFasteners and nuts over38 in. M10 in diameterWashers316 in. 4.7 mm and over in thickness0.0020 in.
49、 50 m 0.0017 in. 43 m 0.0017 in. 43 mFasteners and nuts38 in. M10 and under in diameterWashers under316 in. 4.7 mm in thickness0.0017 in. 43 m 0.0015 in. 38 m 0.0015 in. 38 mAIn the case of long pieces, such as anchor rods and similar articles over 5 ft 1.5 m in length, the thickness measurement shall be determined at each end and themiddle of the article. In the case of a fully threaded rod, the thickness measurements shall be determined at each end of the article. In no case shall the average of themeasurements be be
