1、Designation: A574 16A574 17Standard Specification forAlloy Steel Socket-Head Cap Screws1This standard is issued under the fixed designation A574; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number i
2、n 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 U.S. Department of Defense.1. Scope*1.1 This specification covers the requirements for quenched
3、and tempered alloy steel hexagon socket-head cap screws, 0.060through 4 in. in diameter where high strength is required.1.2 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in thisstandard.1.3 The following hazard caveat pertains only t
4、o the test method portions, sections 5.1, 5.6, 8, and 12, of this specification. Thisstandard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the userof this standard to establish appropriate safety and health practices and determi
5、ne the applicability of regulatory limitations priorto use.1.4 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations iss
6、uedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2A751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel ProductsE112 Test Methods for Determining Average Grain SizeF606/F606M Test Methods for Determining t
7、he Mechanical Properties of Externally and Internally Threaded Fasteners,Washers, Direct Tension Indicators, and RivetsF788 Specification for Surface Discontinuities of Bolts, Screws, and Studs, Inch and Metric SeriesF1470 Practice for Fastener Sampling for Specified Mechanical Properties and Perfor
8、mance InspectionF1789 Terminology for F16 Mechanical FastenersF1940 Test Method for Process Control Verification to Prevent Hydrogen Embrittlement in Plated or Coated FastenersF2282 Specification for Quality Assurance Requirements for Carbon and Alloy Steel Wire, Rods, and Bars for MechanicalFastene
9、rsF2328 Test Method for Determining Decarburization and Carburization in Hardened and Tempered Threaded Steel Bolts,Screws, Studs, and Nuts2.2 ASME Standards:3B18.3 Socket Cap, Shoulder, and Set ScrewsB18.12 Glossary of Terms for Mechanical FastenersB18.24 Part Identifying Number (PIN) Code System S
10、tandard for B18 Fastener Products3. Terminology3.1 Definitions of Terms Specific to This StandardThe definition of terms used in this specification shall be as specified inTerminology F1789,ASME B18.12, or the applicable referenced standards, unless otherwise defined herein. In the event that therea
11、re differences for a given term, ASTM definitions shall be used.1 This specification is under the jurisdiction of ASTM Committee F16 on Fasteners and is the direct responsibility of Subcommittee F16.02 on Steel Bolts, Nuts, Rivetsand Washers.Current edition approved Oct. 1, 2016June 1, 2017. Publish
12、ed November 2016June 2017. Originally approved in 1967. Last previous edition approved in 20132016 asA574 13.A574 16. DOI: 10.1520/A0574-16.10.1520/A0574-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of AST
13、M Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from American Society of Mechanical Engineers (ASME), ASME International Headquarters, ThreeTwo Park Ave., New York, NY 10016-5990,http:/www.asme.org.This document is not an ASTM standard and
14、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 users consult prior editions as appropriate. In all cases only th
15、e 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 Conshohocken, PA 19428-2959. United States14. Ordering Information4.
16、1 Orders for socket head cap screws under this specification shall include the following information:4.1.1 ASTM designation and year of issue.4.1.2 Name of the screw (SHCS).4.1.3 Quantity (number of pieces by size).4.1.4 Dimensions, including nominal thread designation, thread pitch, and nominal scr
17、ew length.4.2 Orders for socket head cap screws shall include the following optional requirements if specified by the purchaser:4.2.1 Inspection at point of manufacture.4.2.2 Coating, if a protective finish other than those, which are described in 5.5 is required, it must be specified (see 5.6).4.2.
18、3 Test reports or certificate of conformance, as required (see Section 15).4.2.4 Additional testing (see 12.1).4.2.5 Special packaging (see 18.1.2).4.2.6 Supplementary requirements (see S1).4.2.7 Special requirements.4.2.8 For establishment of a part identifying system, see ASME B18.24.5. Materials
19、and Manufacture5.1 The screws shall be fabricated from alloy steel made to a fine grain practice. In the event of controversy over grain size,referee tests on finished screws conducted in accordance with Test Methods E112 shall prevail.5.2 Screws in sizes through 0.750 in. diameter, and with lengths
20、 through ten times the nominal product size or 6.0 inches,whichever is shorter, shall be cold headed, except that when specified by the purchaser the screws shall be hot headed. Larger sizesand longer lengths shall be cold or hot headed at the option of the manufacturer, unless otherwise specified b
21、y the purchaser.Screws larger than 1.500 in. nominal diameter shall be permitted to be machined. Sockets shall be forged or machined at the optionof the manufacturer.5.3 Screws in sizes through 0.625 in. diameter, and for product lengths through 4 in. shall be roll threaded, unless otherwisespecifie
22、d by the purchaser. Larger products shall be rolled, cut, or ground at the option of the manufacturer.5.4 Screws shall be heat treated by quenching in oil from above the transformation temperature and then tempered by reheatingto at least 700F to achieve the mechanical properties specified in Sectio
23、n 7 and Table 1.5.4.1 When specified by the purchaser, the minimum tempering temperature shall be verified by subjecting screws to 680F for30 minutes at temperature. The mean cross section hardness of three readings on the screw before and after retempering shall notdiffer by more than 2 points hard
24、ness Rockwell C (HRC).5.5 Standard FinishesUnless otherwise specified, the screws shall be furnished with one of the following “standard surfacesas manufactured” at the option of the manufacturer: (1) bright uncoated, (2) thermal black oxide, or (3) chemical black oxide.Hydrogen embrittlement tests
25、shall not be required for screws furnished in these conditions.5.6 Protective Coatings:5.6.1 When a protective finish other than as specified in 5.5 is required, it shall be specified on the purchase order with theapplicable finish specification.TABLE 1 Mechanical RequirementsProperty #0.5 in.Nom. D
26、ia.0.5 in. and 270,000 Over 3DA B . B ZC . XC YC YC YC YC4 $1.0 in. 270,000 Over 3DA B . B ZC . XD YD YD YD YDA D denotes nominal diameter of product.B Denotes mandatory test.C Proof load test denoted Z shall be conducted when purchaser requests the test in inquiry and order.D Either all tests denot
27、ed by X or all tests denoted by Y shall be performed. In case of arbitration full-size tests, denoted X, shall be decisive. Proof load test denoted Zshall be conducted when purchaser requests the test in inquiry and order.TABLE 4 Tensile Requirements for Coarse Thread ScrewsScrewDia (D),in.Threads/i
28、n.TensileLoad,min, lbf AStressArea,in.2 BProof Load(LengthMeasurementMethod),min, lbf C0.073 64 473 0.00263 3680.086 56 666 0.00370 5180.099 48 877 0.00487 6820.112 40 1 090 0.00604 8460.125 40 1 430 0.00796 1 1100.138 32 1 640 0.00909 1 2700.164 32 2 520 0.0140 1 9600.190 24 3 150 0.0175 2 4500.216
29、 24 4 350 0.0242 3 3800.250 20 5 730 0.0318 4 4500.3125 18 9 440 0.0524 7 3400.375 16 13 900 0.0775 10 8000.4375 14 19 100 0.1063 14 9000.500 13 25 500 0.1419 19 9000.5625 12 30 900 0.182 24 6000.625 11 38 400 0.226 30 5000.750 10 56 800 0.334 45 1000.875 9 78 500 0.462 62 4001.000 8 103 000 0.606 8
30、1 8001.125 7 129 000 0.763 103 0001.250 7 165 000 0.969 131 0001.375 6 196 000 1.155 156 0001.500 6 239 000 1.405 190 0001.750 5 323 000 1.90 256 0002.000 412 425 000 2.50 338 0002.250 412 552 000 3.25 439 0002.500 4 680 000 4.00 540 0002.750 4 838 000 4.93 666 0003.000 4 1 010 000 5.97 806 0003.250
31、 4 1 210 000 7.10 958 0003.500 4 1 420 000 8.33 1 120 0003.750 4 1 640 000 9.66 1 300 0004.000 4 1 880 000 11.08 1 500 000A Values based on 180 ksi for 0.500 and smaller and 170 ksi for sizes larger than0.500 in. and stress area in accordance with Footnote B.B Stress areas based on Handbook H-28 (U.
32、S. Department of Commerce) asfollows:As50.7854 fD2s0.9743/ndg2where:As = stress area,D = nominal screw size, andn = threads/in.C Values based on 140 ksi for 0.500 and smaller and 135 ksi for sizes larger than0.500 in. and stress area in accordance with Footnote B.A574 17410.2.4 Forging cracks locate
33、d in the socket wall within 0.1 times the actual key engagement (T) from the bottom of the socketare not permissible. Discontinuities located elsewhere in the socket shall not have a length exceeding 0.25T, or a maximum depthof 0.03D or 0.005 in., whichever is greater (see Fig. 2).10.3 Seams in the
34、shank shall not exceed a depth of 0.03D or 0.005 in., whichever is greater.10.4 Thread DiscontinuitiesThreads shall have no laps at the root or on the flanks located below the pitch line, as shown inFig. 3, when inspected in accordance with Specification F788, S1.2. Laps are permissible at the threa
35、d crest (Fig. 3C) to a depthof 25 % of the basic thread height and on the thread flanks above the pitch diameter. Longitudinal seams rolled beneath the rootof the thread and across the crests of the threads are acceptable within the limits of 10.3.11. Sampling and Number of Tests11.1 Guide F1470 sha
36、ll be used to determine the necessary sampling plan and the number of tests that must be performed todemonstrate that all of the requirements of this standard are met for each lot.TABLE 5 Tensile Requirements for Fine Thread ScrewsScrewDia (D),in.Threads/in.TensileLoad,min, lbf AStressArea,in.2 BPro
37、of Load(LengthMeasurementMethod)min, lbf C0.060 80 324 0.00180 2520.073 72 500 0.00278 3890.086 64 709 0.00394 5520.099 56 941 0.00523 7320.112 48 1 190 0.00661 9250.125 44 1 490 0.00830 1 1600.138 40 1 830 0.01015 1 4200.164 36 2 650 0.01474 2 0600.190 32 3 600 0.0200 2 8000.250 28 6 500 0.0364 5 1
38、000.216 28 4 600 0.0258 3 6000.3125 24 10 400 0.0580 8 1200.375 24 15 800 0.0878 12 3000.4375 20 21 400 0.1187 16 6000.500 20 28 800 0.1599 22 4000.5625 18 34 500 0.203 27 4000.625 18 43 500 0.256 34 6000.750 16 63 400 0.373 50 4000.875 14 86 500 0.509 68 7001.000 12 113 000 0.663 89 5001.125 12 146
39、 000 0.856 116 0001.250 12 182 000 1.073 145 0001.375 12 224 000 1.315 178 0001.500 12 269 000 1.581 213 000A Values based on 180 ksi for 0.500 and smaller and 170 ksi for sizes larger than0.500 in. and stress area in accordance with Footnote B.B Stress areas based on H-28 as follows:As50.7854 fD2s0
40、.9743/ndg 2where:As = stress area,D = nominal screw size, andn = threads/in.C Values based on 140 ksi for 0.500 and smaller and 135 ksi for sizes larger than0.500 in. and stress area in accordance with Footnote B.TABLE 6 Wedge Test AnglesScrew Size,D, in.Wedge Angle, DegBody Lengths2D or Lessor Thre
41、adedto the HeadBody LengthsGreater than 2D0.112 0.500, incl 6 100.625 0.750, incl 6 80.875 to 1.500, incl 4 6A574 175FIG. 1 Head and Body Discontinuity Location and LimitsFIG. 2 Socket Discontinuity Location and LimitsA574 17612. Test Methods12.1 Testing, to demonstrate that the requirements in 5.4.
42、1, Section 7, or any additional mechanical tests that are required bythe purchaser have been met, shall be in accordance with Test Methods F606/F606M at room temperature.12.2 The inspection and evaluation of surface discontinuities shall be in accordance with the requirements in Specification F788.1
43、2.3 Decarburization and carburization tests shall be conducted in accordance with Test Method F2328, Class 3.13. Inspection13.1 If the inspection described in 13.2 is required by the purchaser, it shall be specified in the inquiry and contract or order.13.2 The purchasers representative, upon reason
44、able notice, shall have free entry to all parts of the manufacturers works, orsuppliers place of business, that concern the manufacture or supply of the material ordered. The manufacturer or supplier shallafford the purchasers representative all reasonable facilities to satisfy him that the material
45、 is being furnished in accordance withthis specification. All tests and inspections required by the specification that are requested by the purchasers representative shallbe made before shipment, and shall be conducted so as not to interfere unnecessarily with the operation of the manufacturersworks
46、 or suppliers place of business.14. Rejection and Rehearing14.1 The disposition of nonconforming lots shall be in accordance with the provisions found in Guide F1470.15. Test Reports15.1 When specified on the Purchase Order, the manufacturer or supplier, whichever is the responsible party as defined
47、 inSection 16, shall furnish a test report or certificate of conformance as specified by the purchaser.15.2 When a test report is specified, it shall include the following:15.2.1 Product description, quantity, ASTM Specification Number and issue date,15.2.2 Name of the manufacturer or responsible pa
48、rty,15.2.3 Purchase order number or other distinguishing information, when required by the purchaser or supplier,15.2.4 Lot number,15.2.5 Alloy grade (AISI, SAE, UNS, etc.), heat analysis and heat number,15.2.6 Report, describe, or illustrate manufacturers or responsible partys markings, if applicab
49、le,15.2.7 Results of hardness, tensile, proof load, yield tests, elongation and reduction of area as applicable,15.2.8 Results of carburization and decarburization,15.2.9 Statement of conformance with surface discontinuity, workmanship and appearance requirements,15.2.10 Statement of conformance dimensionally, and15.2.11 Title and signature of individual assigned test report responsibility.16. Responsibility16.1 The party responsible for the fastener shall be the organization that supplies the fastener to the purchaser.FIG. 3 Thread DiscontinuitiesA574
