1、Designation: F879 10Standard Specification forStainless Steel Socket Button and Flat Countersunk HeadCap Screws1This standard is issued under the fixed designation F879; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of l
2、ast revision. A number in parentheses indicates the year of last reapproval. A superscriptepsilon () 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 chemica
3、l and mechanicalrequirements for stainless steel inch hexagon socket button(SBHCS) and flat countersunk (SFHCS) head cap screws withnominal thread 0.060 through 0.625 in. intended for use inapplications requiring general corrosion resistance.1.2 Two groups of austenitic stainless steel alloys and th
4、reeconditions are covered. See Table 1 and Table 2.1.3 UnitsThe values stated in inch-pound units are to beregarded as standard. No other units of measurement areincluded in this standard.1.4 The following precautionary caveat pertains only to thetest method portion, Section 12, of this specificatio
5、n: 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 healthpractices and determine the applicability of regulatory limita-tions prior to use.2. Referenced Docum
6、ents2.1 ASTM Standards:2A262 Practices for Detecting Susceptibility to IntergranularAttack in Austenitic Stainless SteelsA342/A342M Test Methods for Permeability of FeeblyMagnetic MaterialsA380 Practice for Cleaning, Descaling, and Passivation ofStainless Steel Parts, Equipment, and SystemsA555/A555
7、M Specification for General Requirements forStainless Steel Wire and Wire RodsA751 Test Methods, Practices, and Terminology for Chemi-cal Analysis of Steel ProductsA967 Specification for Chemical Passivation Treatmentsfor Stainless Steel PartsD3951 Practice for Commercial PackagingE18 Test Methods f
8、or Rockwell Hardness of Metallic Ma-terialsE92 Test Method for Vickers Hardness of Metallic Materi-alsE384 Test Method for Knoop and Vickers Hardness ofMaterialsF593 Specification for Stainless Steel Bolts, Hex CapScrews, and StudsF606 Test Methods for Determining the Mechanical Prop-erties of Exter
9、nally and Internally Threaded Fasteners,Washers, Direct Tension Indicators, and RivetsF788/F788M Specification for Surface Discontinuities ofBolts, Screws, and Studs, Inch and Metric SeriesF1470 Practice for Fastener Sampling for Specified Me-chanical Properties and Performance Inspection2.2 ASME St
10、andard:B 18.3 Socket Cap, Shoulder and Set Screws (Inch Series)33. Classification3.1 The designation of the alloy group and condition of thisspecification shall be consistent with the stainless steel desig-nations in Specification F593.3.2 Screws shall be designated by group and condition (forexampl
11、e, F879 Group 1 Condition AF).4. Ordering Information4.1 Orders for material under this specification shall includethe following information:4.1.1 Quantity (number of pieces of each item).4.1.2 Name of the screw, SBHCS or SFHCS.4.1.3 Dimensions, including nominal thread designation,thread pitch, and
12、 nominal screw length (inches). A standardpart number may be used for this definition.4.1.4 Alloy group and condition.4.1.5 Certification, if required (see Section 15).1This specification is under the jurisdiction of ASTM Committee F16 onFasteners and is the direct responsibility of Subcommittee F16
13、.04 on NonferrousFasteners.Current edition approved May 1, 2010. Published June 2010. Originallyapproved in 1986. Last previous edition approved in 2008 as F879 02a(2008).DOI: 10.1520/F0879-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at se
14、rviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Global Engineering Documents, 15 Inverness Way, EastEnglewood, CO 80112-5704, http:/.1*A Summary of Changes section appears at the end of this standard.
15、Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.1.6 ASTM specification and year of issue.4.1.7 Any special or supplemental requirements (seeSupplementary Requirements S1 through S6).5. Materials and Manufacture5.1 Screws shall be fo
16、rmed by upsetting or extruding, orboth.5.2 Screws shall be roll threaded.5.3 Heat TreatmentAustenitic alloys Condition AFscrews, following manufacture, shall be annealed by heating to1900 6 50F to obtain maximum corrosion resistance andminimum permeability. The screws shall be held for a sufficientt
17、ime at temperature, then cooled at a rate sufficient to preventprecipitation of the carbide and provide the properties specifiedin Table 1.5.4 When Condition CW or CW1 is specified, the austeniticalloys shall be annealed as specified in 5.3, generally by theraw material manufacturer, then cold worke
18、d to developspecific properties.6. Chemical Composition6.1 The chemical composition of the screws shall conformto the requirements of Table 2.6.2 Unless otherwise specified in the inquiry and purchaseorder (see Supplementary Requirement S2), the choice of analloy from within a group shall be that of
19、 the fastenermanufacturer as determined by his fabrication methods andmaterial availability. The specific alloy from within a groupused by the manufacturer shall be clearly identified on allcertification required in the purchase order.6.3 When chemical analysis is performed by the purchaserusing fin
20、ished fasteners, the chemical composition obtainedshall conform to the limits specified in Table 2 for the specificalloy. Chemical composition shall conform to the tolerancesspecified in Specification A555/A555M.6.3.1 In the event of a discrepancy, a referee analysis of thesamples for each lot as sp
21、ecified in 12.1 shall be made inaccordance with 11.3.1.7. Mechanical Properties7.1 The finished screws shall conform to the mechanicalrequirements specified in Table 1.7.2 Screws having a nominal length equal to or greater thanthree diameters shall be tensile tested full size and shall meetthe full
22、size breaking strength requirements specified in Table3. Tensile failures through the head are acceptable providingthe load requirements are satisfied.7.3 Screws that are too short (lengths less than specified in7.2 or that have insufficient threads for tension testing) shallnot be subject to tensio
23、n tests, but shall conform to thehardness requirements of Table 1.8. Corrosion Resistance Requirements8.1 Carbide Precipitation:8.1.1 Rod, bar, and wire used to make fasteners in accor-dance with this specification shall be capable of passing the testfor susceptibility to intergranular corrosion as
24、specified inPractice E of Practices A262.8.1.2 As stated in PracticesA262, samples may be subjectedto the faster and more severe screening test in accordance withTABLE 1 Mechanical Property RequirementsAlloy GroupAlloyConditionFull Size Product TestsAMachined Specimen Tests Core HardnessBTensileStre
25、ngth ksiExtensionCminTensileStrength ksiYieldStrength ksiElongation%minVickers RockwellAll AF 85 max 0.6D 85 max 55 max 40 210 max 95 HRB maxAll CW 80 min 0.4D 80 min 40 min 25 150 min 50 HRA minAll CW1 102 min 0.4D 87 min 65 min 20 220 min 59 HRA minAActual full-size testing of condition CW and CW1
26、 may result in decreased tensile strength because of the head configuration (see Table 3). For fasteners with nominalthread diameters larger than 0.625 in., the mechanical properties shall be agreed upon between the user and manufacturer.BCore hardness is only required when full-size product testing
27、 cannot be accomplished.CD denotes nominal thread size.TABLE 2 Chemical RequirementsAlloyGroupUNSDesignationAlloyComposition, % maximum except as shownCarbon Manganese Phosphorus Sulfur Silicon Chromium Nickel Copper MolybdeneunmAustenitic Alloys1 S30400 304 0.08 2.00 0.045 0.030 1.00 18.0 to20.08.0
28、 to10.51.00 . . .1 S30403 304L 0.030 2.00 0.045 0.030 1.00 18.0 to20.08.0 to12.01.00 . . .1 S30500 305 0.12 2.00 0.045 0.030 1.00 17.0 to19.010.5 to13.01.00 . . .1 S38400 384 0.08 2.00 0.045 0.030 1.00 15.0 to17.017.0 to19.0. .1 S30430 189LW 0.10 2.00 0.045 0.030 1.00 17.0 to19.08.0 to10.03.0to4.0 .
29、1 S30433 302HQ 0.03 2.00 0.045 0.030 1.00 17.0 to19.08.0 to10.03.0to4.0 .2 S31600 316 0.08 2.00 0.045 0.030 1.00 16.0 to18.010.0 to14.0. . . 2.00 to 3.02 S31603 316L 0.03 2.00 0.045 0.030 1.00 16.0 to18.010.0 to14.0. . . 2.00 to 3.0F879 102Practice A. Failing Practice A, specimens shall be tested to
30、Practice E and be considered satisfactory if passing Practice E.9. Dimensions9.1 Unless otherwise specified, the dimensions shall con-form to the requirements of ASME B 18.3.10. Workmanship and Finish10.1 Surface TreatmentUnless otherwise specified,screws shall be cleaned, descaled, and passivated i
31、n accordancewith Practice A380 or Specification A967 at the option of themanufacturer.10.2 Surface Discontinuities:10.2.1 The surface discontinuities for these products shallconform to Specification F788/F788M and the additionallimitations specified herein.10.2.1.1 Forging defects that connect the s
32、ocket to theperiphery of the head are not permissible. Defects originatingon the periphery and with a traverse indicating a potential tointersect are not permissible. Other forging defects are permis-sible provided those located in the bearing area, fillet, and topsurfaces shall not have a depth exc
33、eeding 0.03 D or 0.005 in.whichever is greater. For peripheral discontinuities, the maxi-mum depth may be 0.06 D (see Fig. 1).10.2.1.2 Forging defects located in the socket wall within0.1 times the actual key engagement, T, from the bottom of thesocket are not permissible. Discontinuities located el
34、sewhere inthe socket shall not have a length exceeding 0.25 T,oramaximum depth of 0.03 D not to exceed 0.005 in. (see Fig. 2).10.2.1.3 Seams in the shank shall not exceed a depth of 0.03D or 0.008 in. whichever is greater.10.2.1.4 No transverse discontinuities shall be permitted inthe head-to-shank
35、fillet area.10.2.1.5 Threads shall have no laps at the root or on theflanks, as shown in Fig. 3. Laps are permitted at the crests (Fig.3(C) that do not exceed 25 % of the basic thread depth, and onthe flanks outside the pitch cylinder. Longitudinal seams rolledbeneath the root of the thread and acro
36、ss the crests of thethreads are acceptable within the limits of 10.2.1.3.11. Number of Tests11.1 The requirements of this specification shall be met incontinuous mass production for stock and the manufacturershall make sample inspections to ensure that the productconforms to the specified requiremen
37、ts. Additional tests ofindividual shipments of fasteners are not ordinarily necessary.A record of the individual heat of steel in each lot shall bemaintained. The containers shall be coded to permit identifi-cation of the lot.11.2 When specified in the purchase order, the manufacturershall furnish a
38、 test report of the last complete set of chemicalanalysis and mechanical tests for each stock size in eachshipment.11.3 When tests of individual shipments are required,Supplementary Requirement S1 must be specified in theinquiry and order.TABLE 3 Breaking Strength Values for Full Size FastenersNOTE
39、1Breaking loads are based on tensile stress area and strengthsof 85 ksi max (AF), 64 ksi min (CW), and 82 ksi for CW1. The minimumloads for the CW and CW1 conditions are based on the tensile propertiesof 80 ksi minimum material strength and 102 ksi minimum materialstrength, respectively, reduced by
40、20 % to allow for the head criticalnature of these configurations. See Note A in Table 1. Actual strength ofthe threaded section, if size permits, may be determined by removing thehead and testing the threaded section as a stud.Nominal SizeTensile StressArea, in.2Alloy Condition, lb. minAF CW CW10 0
41、.06080 0.00180 153 115 1471 0.07364 0.00263 223 168 2152 0.08656 0.00370 314 237 3033 0.09948 0.00487 414 312 3994 0.11240 0.00604 513 386 4955 0.12540 0.00796 676 509 6526 0.13832 0.00909 772 581 7458 0.16432 0.0140 1191 897 114910 0.19024 0.0175 1490 1122 143814 0.25020 0.0318 2705 2037 2609516 0.
42、31218 0.0524 4457 3356 429938 0.37516 0.0775 6587 4959 635412 0.50013 0.1419 12 061 9082 11 63658 0.62511 0.226 19 210 14 464 18 532FIG. 1 Head Discontinuities (See 10.2.1)FIG. 2 Socket Discontinuities (See 10.2.1)F879 10311.3.1 When the purchaser does not specify the samplingplan and basis of accep
43、tance, the following shall apply:11.3.1.1 The lot, for purposes of selecting samples, shallconsist of all products offered for inspection and testing at onetime that are of the same type, style, nominal diameter, threadpitch, nominal length, material, condition, and surface finish.11.3.1.2 From each
44、 lot, samples shall be selected at randomand tested for each requirement in accordance with thefollowing:Number of Pieces in Lot Number of Samples800 and less 1Over 800 to 8000, incl 2Over 8000 to 22 000, incl 3Over 22 000 511.3.1.3 Should any sample fail to meet the requirements ofa specified test,
45、 double the number of samples from the samelot shall be retested for the requirement(s) in which it failed.All of the additional samples shall conform to the specification,or the lot shall be rejected.11.3.1.4 If the failure of a test specimen is due to improperpreparation of the specimen or an inco
46、rrect testing technique,the specimen shall be discarded and another test specimensubmitted.11.4 Corrosion Resistance Tests:11.4.1 Unless otherwise specified, inspection for corrosionresistance shall be in accordance with the manufacturersstandard quality control practices. No specific method ofinspe
47、ction is required but the screws shall be produced fromsuitable raw material and manufactured by properly controlledpractices to maintain resistance to corrosion. When corrosiontests are required, Supplementary Requirement S5 must bespecified in the inquiry and order, except as noted in 11.4.2.11.4.
48、2 Products that have been hot worked shall be solutionannealed and tested to determine freedom from precipitatedcarbides. Not less than one corrosion test shall be made fromeach lot. Corrosion tests shall be performed in accordance withPractices A262, Practices A or E as applicable.12. Test Methods1
49、2.1 Chemical AnalysisThe chemical composition shallbe determined in accordance with Test Method A751.12.1.1 The fastener manufacturer may accept the chemicalanalysis of each heat of raw material purchased and reported onthe raw material certification furnished by the raw materialproducer. The fastener manufacturer is not required to do anyfurther chemical analysis testing provided that precise heat lottraceability has been maintained throughout the manufacturingprocess on each lot of fasteners produced and delivered.12.2 Mechanical Te
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