ASTM A574M-2011 Standard Specification for Alloy Steel Socket-Head Cap Screws [Metric]《合金钢内六角螺钉的标准规格［米制］》.pdf

1、Designation: A574M 11Standard Specification forAlloy Steel Socket-Head Cap Screws Metric1This standard is issued under the fixed designation A574M; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number

2、 in parentheses indicates the year of last reapproval. Asuperscript epsilon () 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. Scope*1.1 This specification covers the requirements for quenchedand

3、tempered alloy steel hexagon socket-head cap screws, 1.6mm through 48 mm in diameter having a minimum ultimatetensile strength of 1220 MPa.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.NOTE 1This specification is the metri

4、c companion of SpecificationA574.1.3 The following hazard caveat pertains only to the testmethod portions, sections 5.1, 5.6, 8, and 12, of this specifi-cation. This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user o

5、f this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A751 Test Methods, Practices, and Terminology for Chemi-cal Analysis of Steel ProductsE112 Test Methods for Determi

6、ning Average Grain SizeF606M Test Methods for Determining the MechanicalProperties of Externally and Internally Threaded Fasteners,Washers, and Rivets (Metric)F788/F788M Specification for Surface Discontinuities ofBolts, Screws, and Studs, Inch and Metric SeriesF1470 Practice for Fastener Sampling f

7、or Specified Me-chanical Properties and Performance InspectionF1789 Terminology for F16 Mechanical FastenersF1940 Test Method for Process Control Verification toPrevent Hydrogen Embrittlement in Plated or CoatedFastenersF2282 Specification for Quality Assurance Requirementsfor Carbon and Alloy Steel

8、 Wire, Rods, and Bars forMechanical FastenersF2328M Test Method for Determining Decarburization andCarburization in Hardened and Tempered Threaded SteelBolts, Screws and Studs (Metric)2.2 ASME Standards:3B18.3.1M Metric Socket Head Cap ScrewsB18.12 Glossary of Terms for Mechanical FastenersB18.24 Pa

9、rt Identifying Number (PIN) Code System Stan-dard for B18 Fastener Products3. Terminology3.1 Definitions of Terms Specific to This StandardThedefinition of terms used in this specification shall be asspecified in Terminology F1789, ASME B18.12, or the appli-cable referenced standards, unless otherwi

10、se defined herein. Inthe event that there are differences for a given term ASTMdefinitions shall be used.4. Ordering Information4.1 Orders for socket head cap screws under this specifica-tion shall include the following information:4.1.1 ASTM designation and year of issue.4.1.2 Name of the screw (SH

11、CS).4.1.3 Quantity (number of pieces by size).4.1.4 Dimensions, including nominal thread designation,thread, pitch, and nominal screw length (millimeters).4.2 Orders for socket head cap screws shall include thefollowing optional requirements if specified by the purchaser:4.2.1 Inspection at point of

12、 manufacture.4.2.2 Coating, if a protective finish other than those, whichare described in 5.5, is required, it must be specified (see 5.6).4.2.3 Certified test reports, as required (see Section 15).4.2.4 Additional testing (see 12.1).1This specification is under the jurisdiction of ASTM Committee F

13、16 onFasteners and is the direct responsibility of Subcommittee F16.02 on Steel Bolts,Nuts, Rivets and Washers.Current edition approved May 1, 2011. Published May 2011. Originallyapproved in 1980. Last previous edition approved in 2004 as A574M 08. DOI:10.1520/A0574M-11.2For referenced ASTM standard

14、s, 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.3Available from American Society of Mechanical Engineers (ASME), ASMEInternational Headqua

15、rters, 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, United States.4.2.5 Special packaging (see 18.1.2).4.2.6 Suppleme

16、ntary requirements (see S1).4.2.7 Special requirements.4.2.8 For establishment of a part identifying system seeASME B18.24.5. Materials and Manufacture5.1 The screws shall be fabricated from alloy steel made toa fine grain practice. In the event of controversy over grainsize, referee tests on finish

17、ed screws conducted in accordancewith Test Methods E112 shall prevail.5.2 Screws in sizes through M20, and with lengths throughten times the nominal product size or 150 mm, whichever isshorter, shall be cold headed, except that when specified by thepurchaser the screws shall be hot headed. Larger si

18、zes andlonger lengths shall be cold or hot headed at the option of themanufacturer, unless otherwise specified by the purchaser.Screws M42 and larger shall be permitted to be machined.Sockets shall be forged or machined at the option of themanufacturer.5.3 Screws in sizes through M24, and product le

19、ngthsthrough 150 mm inclusive, shall be roll threaded, unlessotherwise specified by the purchaser. Larger products shall berolled, cut, or ground at the option of the manufacturer.5.4 Screws shall be heat treated by quenching in oil fromabove the transformation temperature and then tempered byreheat

20、ing to at least 380C to achieve the mechanical proper-ties specified in Section 7 and Table 1.5.4.1 When specified by the purchaser, the minimum tem-pering temperature shall be verified by subjecting screws to370C for 30 minutes at temperature. The mean cross sectionhardness of three readings on the

21、 screw before and afterretempering shall not differ by more than 20 points Vickers(DPH).5.5 Standard FinishesUnless otherwise specified, thescrews shall be furnished with one of the following “standardsurfaces as manufactured” at the option of the manufacturer:(1) bright uncoated, (2) thermal black

22、oxide, or (3) chemicalblack oxide. Hydrogen embrittlement tests shall not be re-quired for screws furnished in these conditions.5.6 Protective Coatings:5.6.1 When a protective finish other than as specified in 5.5is required, it shall be specified on the purchase order with theapplicable finish spec

23、ification.5.6.2 When protective or decorative coatings are applied tothe screws, precautions specified by the coating requirementsto minimize internal hydrogen embrittlement shall be exer-cised. Additional precautions such as the requirements in TestMethod F1940 and Test Methods F606M shall be by ag

24、reementwith the purchaser.6. Chemical Composition6.1 The screws shall be alloy steel conforming to thechemical composition specified in Table 2 and the require-ments of Specification F2282. See Supplementary Require-ment S1 when additional alloy steel grades are required.6.2 One or more of the follo

25、wing alloying elements: chro-mium, nickel, molybdenum, or vanadium shall be present inthe steel in sufficient quantity to ensure the specified strengthproperties are met after oil quenching and tempering. As aguide for selecting material, an alloy steel should be capable ofmeeting the specified mech

26、anical requirements if the “as oilquenched” core hardness one diameter from the point is equalto or exceeds 25 HRC + (55 3 carbon content).6.3 When product analyses are made by the purchaser fromfinished screws representing each lot, the chemical composi-tion, thus determined, shall conform to the r

27、equirementsprescribed for product analysis in Table 2.6.4 Steel to which bismuth, selenium, tellurium, or lead hasbeen intentionally added shall not be permitted.6.5 Chemical analyses shall be performed in accordancewith Test Methods, Practices, and Terminology A751.7. Mechanical Properties7.1 Socke

28、t head cap screws shall be tested in accordancewith the mechanical testing requirements specified in Table 3,and shall meet the mechanical requirements in Table 1 andTable 4.7.2 The screws that are tested for wedge tensile strengthshall utilize a wedge of the angle specified in Table 5 under thehead

29、. To meet the requirements of the wedge test, there must bea tensile failure in the body or thread section. For the purposeof this test, failure means separation into two pieces. Screwsthreaded to the head shall pass the requirements for this test ifthe fracture that caused failure originated in the

30、 thread area,even though it may have propagated into the fillet area or thehead before separation.8. Metallurgical Requirement8.1 Carburization or Decarburization:8.1.1 There shall be no evidence of carburization or totaldecarburization on the surfaces of the heat-treated screws whenmeasured in acco

31、rdance with Test Method F2328M (Class 4Product).TABLE 1 Mechanical RequirementsProperty Class 12.9AFull-size screws:Tensile or wedge strength, min, MPa 1220Proof load (stress), min, MPa 970Machined test specimen:Yield strength at 0.2 % offset, min, MPa 1100Tensile strength, min, MPa 1220Elongation i

32、n 5D,min,% 10AReduction of area, min, % 35Product hardness:Rockwell 38 to 44 HRCVickers 372 to 434 DPHAElongation is 2 percentage points higher than property class 12.9.TABLE 2 Chemical RequirementsElementComposition, %Heat Analysis Product AnalysisCarbon 0.33 to 0.48 0.31 to 0.50Phosphorus, max 0.0

33、35 0.040Sulfur, max 0.040 0.045Alloying elements See 6.2A574M 1128.1.2 The depth of partial decarburization shall be limited tothe values in Test Method F2328M (Class 4 Product) whenmeasured as described therein.9. Dimensions9.1 Unless otherwise specified, the product shall conform tothe requirement

34、s of ASME B18.3.1M.10. Workmanship, Finish and Appearance10.1 Surface DiscontinuitiesThe surface discontinuitiesfor these products shall conform to Specification F788/F788Mand the additional limitations specified herein.10.2 Forging Cracks:10.2.1 Forging cracks that connect the socket to the periph-

35、ery of the head as shown in Fig. 1 are not permissible.10.2.2 Forging cracks originating on the periphery of thehead and with a traverse indicating a potential to intersect onthe top of the socket head as shown in Fig. 1 are notpermissible.10.2.3 Other forging cracks are permissible provided thoseth

36、at are located in the bearing area, fillet, and top surfaces donot have a depth exceeding 0.03D or 0.13 mm, whichever isgreater. For peripheral discontinuities, the maximum depthshall be 0.06D or 1.6 mm, whichever is greater (see Fig. 1).10.2.4 Forging cracks located in the socket wall within 0.1tim

37、es the actual key engagement (T) from the bottom of thesocket are not permissible. Discontinuities located elsewhere inthe socket shall not have a length exceeding 0.25T,oramaximum depth of 0.03D or 0.13 mm, whichever is greater(see Fig. 2).10.3 Seams in the shank shall not exceed a depth of 0.03Dor

38、 0.13 mm, whichever is greater.10.4 Thread DiscontinuitiesThreads shall have no laps atthe root or on the flanks located below the pitch line, as shownin Fig. 3, when inspected in accordance with SpecificationF788/F788M, S1.2. Laps are permitted at the thread crest (Fig.3C) that do not exceed 25 % o

39、f the basic thread height, and onthe thread flanks above the pitch diameter. Longitudinal seamsrolled beneath the root of the thread and across the crests of thethreads are acceptable within the limits of 10.3.11. Sampling and Number of Tests11.1 Guide F1470 shall be used to determine the necessarys

40、ampling plan and the number of tests that must be performedto demonstrate that all of the requirements of this standard aremet for each lot.12. Test Methods12.1 Testing, to demonstrate that the requirements in 5.4.1,Section 7, or any additional mechanical tests that are requiredby the purchaser have

41、 been met, shall be in accordance withTest Methods F606M at room temperature.12.2 The inspection and evaluation of surface discontinui-ties shall be in accordance with the requirements in Specifica-tion F788/F788M.12.3 Decarburization and carburization tests shall be con-ducted in accordance with Te

42、st Method F2328M, Class 4.TABLE 3 Mechanical Testing RequirementsItem DescriptionTensile Load,min, kNProductLengthHardness,maxHardness,minDecarb/CarburizationTest Conducted UsingFull-Size ProductTest Conducted UsingMachined Test SpecimenProofLoadWedgeTensileStrengthAxialTensileStrengthYieldStrengtha

43、t 0.2 %OffsetTensileStrengthElongationReductionof Area1 All short lengths . . . #3DABB B. . . . . . .2 Smaller SHCS #1200 3D to 300 mmB.BZCXC. . . . .3 Smaller SHCS #1200 Over 300 mmB.BZCXC. YCYCYCYC4 Larger SHCS $1200 3DB.BZC. XCYCYCYCYCAD denotes nominal diameter of product.BDenotes mandatory test

44、.CEither all tests denoted by X or all tests denoted by Y shall be performed. In case of arbitration full-size tests, denoted X, shall be decisive. Proof test denoted Z shallbe conducted when purchaser requests the test in inquiry and order.TABLE 4 Minimum Ultimate Tensile LoadsNOTEAll values are ro

45、unded to 3 significant digits.Thread SizeStress Area,mm2Tensile Load,min, kNProof Load,kNM1.6 3 0.35 1.27 1.55 1.23M2 3 0.4 2.07 2.53 2.01M2.5 3 0.45 3.39 4.14 3.2M3 3 0.5 5.03 6.14 4.88M4 3 0.7 8.78 10.7 8.52M5 3 0.8 14.2 17.3 13.8M6 3 1 20.1 24.5 19.5M8 3 1.25 36.6 44.6 35.5M10 3 1.5 58.0 70.8 56.

46、3M12 3 1.75 84.3 103 81.8M14 3 2 115 140 112M16 3 2 157 192 152M20 3 2.5 245 299 238M24 3 3 353 431 342M30 3 3.5 561 684 544M36 3 4 817 997 792M42 3 4.5 1120 1370 1090M48 3 5 1470 1790 1430TABLE 5 Wedge Test AngleProduct Diameter, mm degreeSocket-head cap screws threaded 2D and through 20 6closer to

47、 underside of head over 20 to 36 4All other socket-head cap screws through 12 10over 12 to 16 8over 16 to 36 6A574M 113FIG. 1 Head and Body Discontinuity Location and LimitsFIG. 2 Socket Discontinuity Location and LimitsA574M 11413. Inspection13.1 If the inspection described in 13.2 is required by t

48、hepurchaser, it shall be specified in the inquiry and contract ororder.13.2 The purchasers representative, upon reasonable no-tice, shall have free entry to all parts of the manufacturersworks, or suppliers place of business, that concern themanufacture or supply of the material ordered. The manufac

49、-turer or supplier shall afford the purchasers representative allreasonable facilities to satisfy him that the material is beingfurnished in accordance with this specification. All tests andinspections required by the specification that are requested bythe purchasers representative shall be made before shipment,and shall be conducted so as not to interfere unnecessarily withthe operation of the manufacturers works or suppliers placeof business.14. Rejection and Rehearing14.1 The disposition of nonconforming lots shall be inaccordance with the provisions found i