1、Designation: A 449 07bStandard Specification forHex Cap Screws, Bolts and Studs, Steel, Heat Treated, 120/105/90 ksi Minimum Tensile Strength, General Use1This standard is issued under the fixed designation A 449; the number immediately following the designation indicates the year oforiginal adoptio
2、n or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Sc
3、ope*1.1 This specification2covers quenched and tempered steelhex cap screws, bolts, and studs having a minimum tensilestrength of 120 ksi for diameters 1.0 in. and smaller; 105 ksi fordiameters over 1.0 in. to 112 in.; and 90 ksi for diameters 134in. to 3.0 in. inclusive. The term 9fasteners9 in thi
4、s specificationdenotes hex cap screws, bolts, and studs.1.2 The fasteners are intended for general engineering use.1.3 The fasteners are furnished in diameters14 to 3.0 in.inclusive. They are designated by type denoting chemicalcomposition as follows:Type DescriptionType I Plain carbon steel, carbon
5、 boron steel, alloysteel, or alloy boron steelType 2 Withdrawn 2003Type 3 Weathering steel1.4 Terms used in this specification are defined in Termi-nology F 1789 unless otherwise defined in this specification.1.5 The values stated in inch-pound units are to be regardedas the standard. The values giv
6、en in parentheses are providedfor information purposes only.1.6 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 applica-b
7、ility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3A 563 Specification for Carbons and Alloy Steel NutsA 751 Test Methods, Practices, and Terminology forChemical Analysis of Steel ProductsB 695 Specification for Coatings of Zinc MechanicallyDeposited on Iron and
8、SteelD 3951 Practice for Commercial PackagingF 436 Specification for Hardened Steel WashersF 606 Test Methods for Determining the Mechanical Prop-erties of Externally and Internally Threaded Fasteners,Washers, Direct Tension Indicators, and RivetsF 788/F 788M Specification for Surface Discontinuitie
9、s ofBolts, Screws, and Studs, Inch and Metric SeriesF 1470 Guide for Fastener Sampling for Specified Mechani-cal Properties and Performance InspectionF 1789 Terminology for F16 Mechanical FastenersF 2329 Specification for Zinc Coating, Hot-Dip, Require-ments for Application to Carbon and Alloy Steel
10、 Bolts,Screws, Washers, Nuts, and Special Threaded FastenersG 101 Guide for Estimating the Atmospheric CorrosionResistance of Low-Alloy Steels2.2 ASME Standards:4B 1.1 Unified Screw ThreadsB 18.2.1 Square and Hex Bolts and ScrewsB 18.24 Part Identifying Number (PIN) Code System Stan-dard for B 18 Fa
11、stener Products3. Ordering Information3.1 Orders for fasteners under this specification shall in-clude the following:3.1.1 Quantity (number of pieces),3.1.2 Size, including nominal diameter and length,3.1.3 Name of product,3.1.4 Type, that is, Type 1, or Type 3 as required,3.1.5 ASTM designation and
12、 year of issue, and3.1.6 Other components such as nuts and washers if re-quired.3.1.7 Hot-Dip or Mechanically Deposited Zinc CoatingsFor hot-dip or mechanically deposited zinc coatings covered by1This specification is under the jurisdiction of ASTM Committee F16 onFasteners and is the direct respons
13、ibility of Subcommittee F16.02 on Steel Bolts,Nuts, Rivets and Washers.Current edition approved Dec. 1, 2007. Published January 2008. Originallyapproved in 1963. Last previous edition approved in 2007 as A 449 07a.2For ASME Boiler and Pressure Vessel Code applications see related Specifi-cations SA-
14、449 in Section II of that Code.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from American Socie
15、ty of Mechanical Engineers (ASME), ASMEInternational Headquarters, Three Park Ave., New York, NY 10016-5990, http:/www.asme.org.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, Unite
16、d States.5.1 and requiring over-tapped nuts, specify the zinc coatingprocess required, that is, hot-dip, mechanically deposited, or nopreference (see 5.1).3.1.8 Other CoatingsSpecify other protective coating ifrequired (see 5.2).3.1.9 Specify if inspection at point of manufacture is re-quired.3.1.10
17、 Test reports if required.3.1.11 Supplementary or special requirements.3.1.12 For establishment of a part identifying system, seeASME B 18.24.NOTE 1A typical ordering description follows: 1000 pieces18 in.diameter 3 4.0 in. long hex cap screw, Type 1, ASTM A 449XX, eachwith one finished hex nut ASTM
18、 A 563, Grade DH. Each componentmechanically zinc coated in accordance with B 695, Class 5, Type II.3.2 Suitable Nuts and Washers:3.2.1 Suitable nuts are covered in Specification A 563.Unless otherwise specified, the grade and style of nut shall beas follows:Fastener Size and Surface Finish Nut Grad
19、e and StyleA14 to 112 in., plain (or with a coating of insufficientthickness to require over-tapped nuts)B, hexOver 112 to 3 in., plain (or with a coating of insuffi-cient thickness to require over-tapped nuts)A, heavy hex14 to 3 in., zinc-coated (or with a coating thicknessrequiring over-tapped nut
20、s)DH, heavy hex14 to 3 in., Type 3 C3, DH3, heavy hexANuts of other grades and styles having specified proof load stresses (Speci-fication A 563, Table 3) greater than the specified grade and style of nut aresuitable.3.2.2 Unless otherwise specified, washers ordered withfasteners shall be furnished
21、to the requirements of SpecificationF 436, Type 1 or Specification F 436, Type 3. Washers forA 449 Type 3 fasteners shall conform to Specification F 436Type 3.4. Materials and Manufacture4.1 Heat Treatment:4.1.1 Type 1 fasteners produced from medium carbon steelshall be quenched in a liquid medium f
22、rom the austenitizingtemperature.4.1.2 Type 1 fasteners produced from medium carbon steelto which chromium, nickel, molybdenum, or boron wereintentionally added, and Type 3 fasteners, shall be quenched inoil from the austenitizing temperature.4.1.3 Type 1 and Type 3 fasteners, regardless of the stee
23、lused, shall be tempered by reheating to not less than 800F.4.2 ThreadingThreads shall be rolled, cut, or ground.4.3 Secondary ProcessingIf any processing which canaffect the mechanical properties of the fasteners is performedafter the initial testing, the fasteners shall be retested for allspecifie
24、d mechanical properties affected by the reprocessing.5. Protective Coatings5.1 Zinc, Hot Dip, and Mechanically Deposited RequiringOver-tapped Nuts:5.1.1 When zinc-coated fasteners are required, the pur-chaser shall specify the zinc-coating process, such as, hot-dip,mechanically deposited, or no pref
25、erence.5.1.2 When hot dip is specified, the fasteners shall be zinccoated by the hot-dip process in accordance with the require-ments of Specification F 2329.5.1.3 When mechanically deposited is specified, the fasten-ers shall be zinc coated by the mechanical deposition processin accordance with the
26、 requirements of Class 55 of Specifica-tion B 695.5.1.4 When no preference is specified, the supplier mayfurnish either a hot-dip zinc coating in accordance withSpecification F 2329, or a mechanically deposited zinc coatingin accordance with Specification B 695, Class 55. Threadedcomponents (bolts a
27、nd nuts) shall be coated by the same zinccoating process, and the suppliers option shall be limited toone process per item with no mixed processes in a lot.NOTE 2When the intended application requires that assembled ten-sion exceeds 50 % of minimum bolt or stud proof load, an anti-gallinglubricant m
28、ay be needed. Application of such a lubricant to nuts and a testof the lubricant efficiency are provided in Supplementary Requirement S1of Specification A 563 and should be specified when required.5.2 Other Coatings:5.2.1 When other coatings are required, the purchaser shallspecify the coating speci
29、fication, including the classificationcodes or grade numbers to identify the coating material,thickness, supplemental treatments, or other requirements todefine the coating. The fasteners shall be coated in accordancewith and conform to the specified coating specification.5.2.2 When a specification
30、does not apply, the purchasershall specify the desired coating, coating thickness, supplemen-tal treatments, or other requirements to define the coating.6. Chemical Composition6.1 Type 1 fasteners shall be plain carbon steel, carbonboron steel, alloy steel, or alloy boron steels, at the manufac-ture
31、rs option, conforming to the requirements in Table 1.6.2 Type 3 fasteners shall be weathering steel and shallconform to one of the chemical compositions specified in Table2. The selection of the chemical composition, A, B, C, D, E orF, shall be a the option of the manufacuturer. See Guide G 101for m
32、ethods of estimating the atmospheric corrosion resistanceof low alloy steel.6.3 Product analyses made on finished fasteners represent-ing each lot shall conform to the product analysis requirementsspecified in Table 1 or Table 2, as applicable.6.4 Heats of steel to which bismuth, selenium, tellurium
33、, orlead has been intentionally added shall not be permitted forbolts. Compliance shall be based on certification that heats ofsteel having any of the listed elements intentionally added werenot used to produce the bolts.6.5 Chemical analyses shall be performed in accordancewith Test Methods, Practi
34、ces, and Terminology A 751.7. Mechanical Properties7.1 HardnessThe fasteners shall conform to the hardnessspecified in Table 3. See Table 3, Note A.7.2 Tensile Properties:A 449 07b27.2.1 Except as permitted in 7.2.2 for long fasteners and7.2.3 for short fasteners, hex cap screws and hex and squarehe
35、ad bolts in sizes 1.00 in. and smaller having a length of 214D and longer and sizes 118 to 112 in. inclusive having a lengthof 3D and longer shall be wedge tested full size. Bolts withheads other than hex or square shall be axially tested. Bothwedge and axially tested hex cap screws and bolts shallc
36、onform to the proof load or alternative proof load, andminimum wedge tensile load in Tables 4 and 5, as applicable.The load applied during proof load testing shall be equal to orgreater than the proof load in Table 4 or Table 5 as applicable.7.2.2 Hex cap screws and square head bolts larger than 112
37、in. diameter, other than those excepted in 7.2.3, shall preferablybe tested full size and when so tested shall conform to thetensile strength and either the specified proof load or yieldstrength requirements in Tables 4 and 5, as applicable. Whenequipment of sufficient capacity for full size testing
38、 is notavailable, or when the length of the bolt makes full size testingimpractical, machined specimens shall be tested and shallconform to the requirements of Table 6.7.2.3 Sizes 1.00 in. and smaller having a length shorter than214 D down to 2D inclusive, which cannot be wedge tensiletested shall b
39、e axially tension tested full size and shall conformto the minimum tensile load and proof load or alternate proofload specified in Tables 4 and 5. Sizes 1.00 in. and smallerhaving a length shorter than 2D which cannot be axially tensiletested shall be qualified on the basis of hardness.7.2.4 Studs 3
40、D and longer shall be axially tension tested fullsize and shall conform to the tensile and proof load or alternateproof load specified in Table 4 and Table 5, as applicable.When equipment for full size testing is not available, or whenthe studs are too long for full size testing, machined specimenss
41、hall be tested and shall conform to the tensile requirements inTable 6.7.2.5 If fasteners are subjected to both hardness and tensiletests, the tensile test results shall take precedence in the eventof low hardness test results.7.2.6 If fasteners are subjected to both full size and ma-chined specimen
42、 tests, the full size test results shall takeprecedence if the results of the two methods differ.8. Dimensions8.1 Head and Body:8.1.1 Hex Cap ScrewsUnless otherwise specified, hex capscrews shall be furnished with dimensions conforming toASME B 18.2.1.8.1.2 BoltsWhen styles other than specified in 8
43、.1.1 arerequired, they shall have dimensions conforming to thosespecified by the purchaser.8.1.3 StudsStuds shall have dimensions conforming tothose specified by the purchaser.8.2 Threads:8.2.1 UncoatedUnless otherwise specified, uncoatedthreads shall be the Unified Coarse Thread Series as specified
44、in the latest issue of ASME B 1.1, and shall have Class 2Atolerances.8.2.2 CoatedUnless otherwise specified, zinc-coatedbolts, to be used with zinc-coated nuts or tapped holes, whichare tapped oversize in accordance with Specification A 563,shall have UNC Class 2A threads before hot-dip or mechani-c
45、ally deposited zinc-coating. After zinc coating, the pitchdiameter and major diameter shall not exceed the Class 2Alimits by more than the following amounts:Nominal Diameter, in.Oversize Limit, in.AHot-Dip Zinc Mechanical Zinc14 0.016 0.012516 ,38 0.017 0.012716 ,12 0.018 0.012916 ,58 ,34 0.020 0.01
46、378 0.022 0.0151.0to114 0.024 0.016138 ,112 0.027 0.018134 to 3.0, incl 0.050 0.033AHot-dip zinc nuts are tapped oversize after coating and mechanical zinccoated nuts are tapped oversize before coating.8.2.3 Unless otherwise specified, fasteners electroplated ormechanically coated to 0.0005 in. or l
47、ess, threads prior toplating shall conform to ASME B 1.1 Class 2A and afterTABLE 1 Chemical Requirements for Type 1 FastenersElementCarbon SteelHeat Analysis Product AnalysisCarbon 0.300.52 0.280.55Manganese, min 0.60 0.57Phosphorus, max 0.040 0.048Sulfur, max 0.050 0.058Silicon 0.0150.30 0.130.32El
48、ementCarbon SteelHeat Analysis Product AnalysisCarbon 0.300.52 0.280.55Manganese, min 0.60 0.57Phosphorus, max 0.040 0.048Sulfur, max 0.050 0.058Silicon 0.100.30 0.080.32Boron 0.00050.003 0.00050.003ElementCarbon SteelHeat Analysis Product AnalysisCarbon 0.300.52 0.280.55Manganese, min 0.60 0.57Phos
49、phorus, max 0.035 0.040Sulfur, max 0.040 0.045Silicon 0.150.35 0.130.37Alloying ElementsAAElementCarbon SteelHeat Analysis Product AnalysisCarbon 0.300.52 0.280.55Manganese, min 0.60 0.57Phosphorus, max 0.035 0.040Sulfur, max 0.040 0.045Silicon 0.150.35 0.130.37Boron 0.00050.003 0.00050.003Alloying ElementsAAASteel, as defined by theAmerican Iron and Steel Institute, shall be consideredto be alloy when the maximum of the range given for the content of alloyingelements exceeds one or more of the following limits: manganese
