ASTM F2329 F2329M-2015 Standard Specification for Zinc Coating Hot-Dip Requirements for Application to Carbon and Alloy Steel Bolts Screws Washers Nuts and Special Threaded Fastene.pdf

1、Designation: F2329 13F2329/F2329M 15Standard 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;F2329/F2329M; the number immediately follow

2、ing the designation indicatesthe year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specificatio

3、n covers the requirements for hot-dip zinc coating applied to carbon steel and alloy steel bolts, screws,washers, nuts, and special threaded fasteners. It also provides for minor coating repairs. Nails and rivets are not included in thisspecification.1.2 It is intended to be applicable to fasteners

4、that are centrifuged or otherwise handled to remove excess galvanizing bath metal(free zinc).1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem may not be exact equivalents; therefore, each system shall be used inde

5、pendently of the other. Combining values from thetwo systems may result in non-conformance with the standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety

6、 and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A153/A153M Specification for Zinc Coating (Hot-Dip) on Iron and Steel HardwareA394 Specification for Steel Transmission Tower Bolts, Zinc-Coated and BareA563 Specifi

7、cation for Carbon and Alloy Steel NutsA563M Specification for Carbon and Alloy Steel Nuts (Metric)A780A780/A780M Practice for Repair of Damaged and Uncoated Areas of Hot-Dip Galvanized CoatingsB487 Test Method for Measurement of Metal and Oxide Coating Thickness by Microscopical Examination of Cross

8、 SectionE376 Practice for Measuring Coating Thickness by Magnetic-Field or Eddy-Current (Electromagnetic) Testing MethodsF606F606/F606M Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners,Washers, and Rivets (Metric) F0606_F0606M Direct Tension Indi

9、cators, and RivetsF606M Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, andRivets (Metric)F1470 Practice for Fastener Sampling for Specified Mechanical Properties and Performance InspectionF1789 Terminology for F16 Mechanical Fasteners

10、3. Terminology3.1 Definitions:3.1.1 Terms used in this specification are defined in Terminology F1789 unless otherwise defined in this specification.3.1.2 batch lotquantity of identical parts cleaned, pickled, fluxed, and galvanized together at one time in a galvanizing basket.3.1.3 galvanizinghot-d

11、ip zinc coating.1 This specification is under the jurisdiction of ASTM Committee F16 on Fasteners and is the direct responsibility of Subcommittee F16.03 on Coatings on Fasteners.Current edition approved June 1, 2013July 1, 2015. Published June 2013September 2015. Originally approved in 2005. Last p

12、revious edition approved in 20112013 asF2329-11.F2329-13. DOI: 10.1520/F2329-13.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page o

13、n the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that user

14、s consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshoh

15、ocken, PA 19428-2959. United States13.1.4 high temperature galvanizinggalvanizing process carried out in a ceramic vessel (kettle) at an approximate temperatureranging between 990F and 1040F 530C and 560C.3.1.5 hot-dip zinc coating of mechanical fastenersprocess whereby fasteners are zinc coated by

16、immersion in a bath of moltenzinc, resulting in the formation of the iron/zinc alloy coating and a zinc coating at the surface of the fastener. This process involvesthe removal of excess zinc by spinning the parts in a centrifuge, or brushing the threaded portion, or handling otherwise to removethe

17、excess zinc.3.1.6 production lotbatches of parts originating from the same manufacturing lot, processed continuously through cleaning,pickling, fluxing, dipping in molten zinc and spun in a centrifuge, or other means, without any significant change in time,temperature, and concentration of the const

18、ituents of the process.3.1.7 stress reliefprocess of heating parts for a definite time at a given temperature in order to relieve stress induced by workhardening.4. Ordering Information4.1 Orders for zinc coating of fasteners to this specification shall include the following:4.1.1 Name of product (t

19、hat is bolt, stud, nut, washers, or other);4.1.2 ASTM designation and year of issue, including fastener specification number;4.1.3 Hydrogen embrittlement relief treatment, as required by the purchaser (see, 7.2.3);4.1.4 Quantity of fasteners to be hot-dip zinc coated;4.1.5 Stress relief or tempering

20、 temperature to which the fasteners where subjected, if applicable;4.1.6 Secondary processing such as chromating, phosphating, or lubrication, if applicable;4.1.7 Average galvanizing temperature to which fasteners will be subjected, if required by the purchaser (see 7.2.2);4.1.8 Specify baking if re

21、quired (see 7.2.3); and4.1.9 Certification, if required (see 14.1).4.1.10 Supplementary Requirements (See S1).5. Materials and Manufacture5.1 Condition of the As-Received FastenersThe fasteners as received by the galvanizer shall be free from contaminants thatare not readily removed in the cleaning

22、process and would adversely affect the galvanizing.5.2 ProcessUnless otherwise covered in this specification, all processing parameters shall be in accordance with therequirements of Specification A153/A153M.5.2.1 Process ControlGalvanized fasteners subjected to a process control plan based upon bat

23、ch lot level shall comply withthe batch lot sampling plan in Table 1, and the sampling plan for production lot (prevention process) as determined in 10.2.2 shallbe applied.5.3 Spinning and Quenching:5.3.1 Parts shall be spun immediately following removal from the galvanizing bath and quenched in wat

24、er. In addition, smallparts shall be air cooled, as needed, in order to prevent the formation of zinc oxide.5.3.2 Parts, which cannot be spun shall be brushed or handled otherwise to remove the excess zinc.5.4 Alteration of Threaded Fasteners:5.4.1 Fasteners that have been hot-dip galvanized shall n

25、ot be further altered (such as subjected to a cutting, rolling, orfinishing-tool operation) by the galvanizer unless specifically authorized in writing by the purchaser.5.4.2 Hot-dip galvanizing of externally threaded fasteners shall meet the thread fitting requirements of the specified productstand

26、ard or specific allowance as determined by the customer.TABLE 1 Process Control of Batch LotASampling PlanSample SizeBBatch Lot Size Average CoatingThicknessCAdhesion AppearanceD5 to 25 1 1 126 to 50 1 1 251 to 150 2 1 2151 and over 2 2 2A The acceptance criterion in all cases is zero defects.B The

27、sample size is the number of specimen(s) required to be tested/inspected tothe applicable criteria.C Frequency of coating thickness measurements: one set of specimen(s) for everyfive batch lots. For test method, see 11.1.D Visual inspection for conformance.F2329/F2329M 152NOTE 1The scope of this spe

28、cification does not cover the requirements regarding the overtapping of galvanized nuts. These requirements areestablished by the applicable product standard, such as Specification A563, Specification A563M (or others), or in writing by the purchaser, if needed.5.5 Secondary Processing:5.5.1 When re

29、quested by the purchaser, treatments such as chromating or phosphating shall be applied to reduce the possibilityof wet storage staining (white corrosion) or to assist subsequent painting.5.5.2 When specified on the purchase order, the nuts, bolts, or screws shall be lubricated to enhance assembly.5

30、.6 Touch-up and RepairBare, cut, or damaged spots found on fasteners after galvanizing, totaling less than 1% of the coatedsurface area, may be repaired with paints containing zinc dust. Such paints shall have zinc-dust concentrations of 65 to 69% orconcentrations above 92% in the dried film. The re

31、pairing party shall select the paint and follow its application instructions. Theapplied coating shall provide barrier protection, and preferably be anodic to steel. Thickness measurements of repaired areas shallnot be required.NOTE 2Experience shows that, in general, organic zinc-rich systems are t

32、olerant of marginal surface preparation and are not critical of climactic oratmospheric conditions for curing. Corrosion resistance and service performance are very dependent on the properties of the paint system, the extent ofsurface preparation, and the skills of individual applicators. See Practi

33、ce A780A780/A780M.6. Chemical Composition of Zinc6.1 Unless otherwise specified in the product standard, the zinc used for the coating shall conform to the requirements of thesection on Zinc of Specification A153/A153M.7. Safeguards Against Alteration of Fasteners Mechanical Properties7.1 Stress Rel

34、iefFasteners subjected to severe work hardening shall be stress-relieved by the fastener manufacturer prior tohot-dip zinc coating (galvanizing).7.2 Hot-Dip Zinc Coating:7.2.1 Effect of Temperature on Mechanical Properties:7.2.1.1 Galvanizing carried out at a temperature above 800F 425C can adversel

35、y affect the final mechanical properties ofthe fasteners. Therefore, the supplier of the fasteners submitting the product to the galvanizer shall be aware of the temperingtemperature of the fasteners relative to the temperature of the galvanizing bath and the potential effect it may have on the prod

36、uct.When requested by the purchaser, the average galvanizing temperature that the fasteners will be subjected to shall be furnished.7.2.1.2 Unless otherwise required by the product standard or by the purchaser, testing for mechanical properties is not necessaryif the galvanizing process is carried o

37、ut at a lower temperature than the stress relief or tempering temperature of the fasteners. Ifthe galvanizing process is carried out at a higher temperature than the stress relief or the tempering temperature of the fasteners,than the purchaser shall make provision for mechanical testing.7.2.1.3 Thr

38、eaded fasteners made from carbon or alloy steel heat treated to a minimum specified hardness of 40 HRC, or casehardened steel fasteners shall not be hot-dip zinc coated.7.2.2 Effect of Hydrogen on the Mechanical Properties after GalvanizingHydrogen has the potential of being introduced intothe steel

39、 during acid pickling, prior to hot-dip galvanizing. For high strength fasteners (having a specified minimum producthardness of 33 HRC), there is a risk of internal hydrogen embrittlement. If required by the product standard or by the purchaser,mechanical descaling (with or without flash pickling) o

40、r baking shall be conducted to reduce the risk of internal hydrogenembrittlement. Baking shall be conducted after pickling and prior to hot-dip galvanizing.7.2.3 Effect of the Galvanizing TemperatureExternally threaded ferrous fasteners over 1.00 in. M24 diameter with aspecified minimum hardness of

41、HRC 33 and higher shall not be hot-dip zinc coated at high temperature (see definition in 3.1.4)in order to avoid microcracks.8. Coating and Dimensional Requirements8.1 Coating ThicknessThe zinc coating thickness shall meet the requirements of Table 2. See Supplementary Requirement S1when specifying

42、 coating thickness for fasteners meeting the requirements of Specification A394.8.2 DimensionThe dimensional characteristics of the fasteners shall be in accordance with the requirements of the purchaser,when specified in the order.The purchaser shall ensure that the effect of the heat generated by

43、the galvanizing process is compatiblewith the fastener regarding the final dimensional characteristics of the parts. Furthermore, the galvanizer shall not be heldresponsible for any unanticipated distortion of parts. In addition, the purchaser shall provide fasteners having sufficient dimensionalall

44、owance to accommodate the zinc thickness deposition, as required in 8.1.8.3 Adhesion of Zinc CoatingThe zinc coating shall adhere tenaciously to the surface of the base metal.The method for testingthe condition of adherence is specified in 11.5.9. Workmanship, Finish, and Appearance9.1 Appearance of

45、 Zinc Coating:F2329/F2329M 1539.1.1 After hot-dip galvanizing, the fasteners shall meet the requirements of the section on Workmanship, Finish, andAppearance of Specification A153/A153M. Galvanized washers shall not be bonded to each other (See Note 3). Parts may be dulldue to the presence of silico

46、n in the steel. The dull appearance shall not be cause for rejection.NOTE 3Hot-dip washers tend to bond to each other. Suitable acceptance criteria shall be agreed between the purchaser and the galvanizer beforeplacing the order. Unless otherwise agreed to in the purchase order, delivered galvanized

47、 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 reasonably uniform in thickness, as defined in the section on Workmanship, Finish,and Appearance of Specification A153/A153M. Sm

48、oothness of a surface is a relative term. Minor roughness that does not impairthe intended use of the part, or roughness that is related to the uncoated surface condition of the part, shall not constitute groundsfor rejection of the parts.9.2.2 The test method shall be in accordance with 11.3.10. Sa

49、mpling10.1 Test specimens shall be selected at random from each production lot or batch lot, when applicable.10.2 Selection of the Sampling PlanProduction LotTwo sampling plans are proposed, one based on detection process andone based on prevention process as defined in Terminology F1789. The selection of the sampling plan shall be in accordance withGuide F1470.10.2.1 Production LotDetection ProcessSampling for coating thickness and for visual appearance shall be conducted inaccordance with Table 1, Sample Level A, and Table 3, Sample Size A, of