1、Designation: F835 12F835 13Standard Specification forAlloy Steel Socket Button and Flat Countersunk Head CapScrews1This standard is issued under the fixed designation F835; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year o
2、f last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () 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 req
3、uirements for quenched and tempered alloy steel hexagon socket button (SBHCS) 0.060through 0.625 thread sizes and flat countersunk (SFHCS) 0.060 through 1.5 thread sizes head cap screws having material propertiesfor high-strength requirements.1.2 Fasteners meeting this specification are intended for
4、 shear-type applications and have tensile requirements ranging from 122to 150 ksi.1.3 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in thisstandard.1.4 The hazard statement applies only to the test method section, Section 11, of this
5、 specification. This standard does notpurport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard toestablish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.2. Re
6、ferenced Documents2.1 ASTM Standards:2A751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel ProductsD3951 Practice for Commercial PackagingE3 Guide for Preparation of Metallographic SpecimensE18 Test Methods for Rockwell Hardness of Metallic MaterialsE112 Test Methods for Dete
7、rmining Average Grain SizeE384 Test Method for Knoop and Vickers Hardness of MaterialsF606MF606 Test Methods for Determining the Mechanical Properties of Externally and InternallyThreaded Fasteners,Washers,Direct Tension Indicators, and Rivets (Metric)F788/F788M Specification for Surface Discontinui
8、ties of Bolts, Screws, and Studs, Inch and Metric Series2.2 ASME Standards:3B18.3 Socket Cap, Shoulder and Set ScrewsInch SeriesB18.24 Part Identifying Number (PIN) Code System Standard for B18 Fastener Products3. Ordering Information3.1 Orders for material under this specification shall include the
9、 following:3.1.1 Quantity (number of screws).3.1.2 Dimensions, including nominal thread designation, thread pitch, and nominal screw length (inches). A standard partnumber may be used for this definition.3.1.3 Name of the screw: SBHCS or SFHCS.1 This specification is under the jurisdiction of ASTM C
10、ommittee F16 on Fasteners and is the direct responsibility of Subcommittee F16.02 on Steel Bolts, Nuts, Rivetsand Washers.Current edition approved May 1, 2012Nov. 1, 2013. Published June 2012January 2014. Originally approved in 1986. Last previous edition approved in 20042012 asF835 04F835 12. 1. DO
11、I: 10.1520/F0835-12.10.1520/F0835-13.2 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 on the ASTM website.3 Available from America
12、n Society of Mechanical Engineers (ASME), ASME International Headquarters, Three Park Ave., New York, NY 10016-5990, http:/www.asme.org.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 vers
13、ion. 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 the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes sect
14、ion appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.4 Coating, if required. If a protective finish other than black oxide is required, it must be specified on the order or productstandard.3.1.5 L
15、ot testing, if required (see 10.3).3.1.6 Certification, if required (see 14.1).3.1.7 ASTM designation and year of issue.3.1.8 Any special requirements.3.1.9 For establishment of a part identifying system, see ASME B18.24.3.2 Example1000 pieces 0.250 20 0.375 SBHCS lot tensile test. ASTM F835XX.4. Ma
16、terials and Manufacture4.1 The screws shall be fabricated from alloy steel made to 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.4.2 Screws shall be hot or cold upset or extruded, or both
17、.4.3 Unless otherwise specified, threads shall be rolled for diameters through 0.625 in. and for screw lengths through 4 in. Fordiameters and lengths other than this, threads may be rolled, cut or ground.4.4 Screws shall be heat treated by quenching in oil from above the transformation temperature a
18、nd then tempering by reheatingto at least 650F to be within the hardness range specified in Table 1.4.4.1 The minimum tempering temperature may be verified by submitting screws to 635F for 30 min at temperature. Theaverage cross-section hardness of three readings on the screw before and after retemp
19、ering shall not differ by more than 20 DPH.4.5 When protective or decorative coatings are applied to the screws, precautions as required by the coatings shall be taken toprevent embrittlement.5. Chemical Composition5.1 The chemical composition of the screw material shall conform to the heat analysis
20、 specified in Table 2.5.2 One or more of the following alloying elements, chromium, nickel, molybdenum, or vanadium, shall be present in the steelin sufficient quantity to ensure the specific strength properties are met after oil quenching and tempering. The steel shall meet theAISI definition of al
21、loy steel, that is, maximum and minimum element content requirement or minimum element limits specified.5.3 Steel to which bismuth, selenium, tellurium, or lead has been added intentionally shall not be permitted.5.4 Material analysis may be made by the purchaser from finished products and the chemi
22、cal composition thus determined shallconform to the requirements specified for the product analysis in Table 2.6. Mechanical Properties6.1 The finished screws shall conform to the mechanical requirements specified in Table 1.6.2 Screws having a nominal length equal to or greater than 3 diameters sha
23、ll be tested full size and shall conform to the full-sizetensile requirements specified in Table 3. Tensile failures through the head are acceptable provided the load requirements aresatisfied.6.3 Screws having a nominal thread diameter-length combination as specified in 6.2 and a breaking load exce
24、eding 200 000 lbpreferably shall be tested full size and shall meet the full-size tensile properties in Table 3. When equipment of sufficient capacityfor such tests is not available or if excessive length of the screws makes full-size testing impractical, standard round machinedTABLE 1 Mechanical Re
25、quirementsNominal Thread Size, in.0.500 andsmallerOver 0.500Full-size Screws:Tensile, min, ksi 145 135Machined Test Specimen:Yield strength at 0.2 % offset, min, ksi A 153Tensile strength, min, ksi A 170Elongation in 4 D, min, % A 8Reduction of area, min, % A 35Product Hardness:Rockwell C 3944 3744V
26、ickers DPH 382434 363434A Not applicable.F835 132specimens may be used that shall meet the machined test specimen tensile properties in Table 1. If discrepancy between full-sizeand machined specimen results, full-size tests shall be used as the referee method to determine acceptance.6.4 Screws that
27、are too short (lengths less than three times nominal size) or that have insufficient threads for tension testing shallnot be subject to tension tests but shall conform to the hardness (minimum and maximum) requirements of Table 1.6.5 All screws, regardless of size, shall conform to the hardness spec
28、ified in Table 1. Hardness shall be met anywhere on thecross section through the threaded portion one diameter from the screw point.7. Other Requirements7.1 Decarburization:7.1.1 There shall be no evidence of carburization or gross decarburization on the surfaces of the heat-treated screws whenmeasu
29、red in accordance with 11.5.7.1.2 The depth of partial decarburization shall be limited to the values in Table 4 when measured as shown in Fig. 1, and inaccordance with 11.5.7.2 EmbrittlementCoated screws shall withstand the embrittlement test in accordance with 11.4 without showing indicationsof di
30、scontinuities. The loading shall be calculated with minimum screw tensile requirements.8. Dimensions8.1 Unless otherwise specified, the dimensions shall conform to the requirements of ASME B 18.3.9. Workmanship, Finish, and Appearance9.1 Surface FinishThe screws shall have a black (thermal or chemic
31、al) oxide finish, unless otherwise specified.9.2 Surface Discontinuities:9.2.1 The surface discontinuities for these products shall conform to Specification F788/F788M and the additional limitationsspecified herein.9.2.2 Forging defects that connect the socket to the periphery of the head are not pe
32、rmissible. Defects originating on theperiphery and with a traverse indicating a potential to intersect are not permissible. Other forging defects are permissible, providedthose located in the bearing area, fillet and top surfaces shall not have a depth exceeding 0.03 D or 0.005 in., whichever is gre
33、ater.For peripheral discontinuities, the maximum depth may be 0.06 D not to exceed 0.040 in. (seeFig. 2).9.2.3 Forging defects located 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 s
34、hall not have a length exceeding 0.25 T or a maximum depthof 0.03 D not to exceed 0.005 in. (seeFig. 3).9.2.4 Seams in the shank shall not exceed a depth of 0.03 D or 0.008 in., whichever is greater.9.2.5 No transverse discontinuities shall be permitted in the head-to-shank fillet area.9.2.6 Threads
35、 shall have no laps at the root or on the flanks, as shown in Fig. 4. Laps are permitted at the crest (Fig. 4c) thatdo not exceed 25 % of the basic thread depth and on the flanks outside the pitch cylinder. Longitudinal seams rolled beneath theroot of the thread and across the crests of cut threads
36、are acceptable within the limits of 9.2.4.9.2.7 Quench cracks of any depth, any length, or in any location are not permitted.10. Number of Tests10.1 The requirements of this specification shall be met in continuous mass production for stock, and the manufacturer shallmake sample inspections to ensur
37、e that the product conforms to the specified requirements.Additional tests of individual shipmentsof material are not ordinarily contemplated.Arecord of individual heats of steel in each test lot shall be maintained. The containershall be coded to permit identification of the lot.10.2 When specified
38、 in the order, the manufacturer shall furnish a test report certified to be the last complete set of mechanicaltests for each stock size in each shipment.TABLE 2 Chemical RequirementsElementComposition, %HeatAnalysisProductAnalysisCarbon 0.30 to 0.48 0.28 to 0.50Phosphorus, max 0.035 0.040Sulfur, ma
39、x 0.040 0.045Alloying elements see 5.2 see 5.2F835 13310.3 When additional tests are specified on the purchase order, a lot, for purposes of selecting test samples, shall consist of allscrews offered for inspection at one time of one diameter and length. From each lot, the number of samples for each
40、 requirementshall be as follows:Number of Pieces in LotNumber ofSamples800 and less 1Over 800 to 8000, incl 2Over 8000 to 22 000, incl 3Over 22 000 510.4 Should any sample fail to meet the requirements of a specified test, double the number of samples from the same lot shallbe retested for the requi
41、rement(s) in which it failed.All of the additional samples shall conform to the specification or the lot shallbe rejected.TABLE 3 Minimum Ultimate Tensile LoadsThread Size Stress Area, in.2Button and CountersunkHeads, Tensile Load,min lbACoarse Fine Coarse FineCoarseThreadSeriesFine ThreadSeries. .
42、. 0.060-80 . . . 0.00180 . 2600.073-64 0.073-72 0.00263 0.00278 380 4000.086-56 0.086-64 0.00370 0.00394 540 5700.099-48 0.099-56 0.00487 0.00523 710 7600.112-40 0.112-48 0.00604 0.00661 880 9600.125-40 0.125-44 0.00796 0.00830 1150 12000.138-32 0.138-40 0.00909 0.01015 1320 14700.164-32 0.164-36 0.
43、0140 0.10474 2030 21400.190-24 0.190-32 0.0175 0.0200 2540 29000.250-20 0.250-28 0.0318 0.0384 4610 52750.3125-18 0.3125-24 0.0524 0.0580 7600 84500.375-16 0.375-24 0.0775 0.0878 11 200 127000.4375-14 0.4375-20 0.1063 0.1187 15 400 170000.500-13 0.500-20 0.1419 0.1599 20 600 232000.625-11 0.625-18 0
44、.226 0.258 30 500 345000.750-10 0.750-16 0.334 0.373 45 100 507000.875-9 0.875-14 0.462 0.509 62 400 692001.000-8 1.000-12 0.606 0.663 81 800 904001.125-7 1.125-12 0.763 0.858 103 000 1164001.250-7 1.250-12 0.969 1.073 131 000 1460001.375-6 1.375-12 1.155 1.315 156 000 1790001.500-6 1.500-12 1.405 1
45、.581 190 000 215000A Because of the head critical configuration of these parts, the full size tensile loads are based on 80 % of the minimum heat treated material strength (180 ksi for sizes0.500 in. and smaller and 170 ksi for sizes larger than 0.500 in.) and the stress areas for coarse thread scre
46、ws.TABLE 4 Decarburization LimitsThreads/in. ThreadHeight, hs0.75 hs fromRoot toCrest, min0.1 hs atRoot, max48 0.013 0.010 0.00144 0.014 0.011 0.00140 0.015 0.011 0.00236 0.017 0.013 0.00232 0.019 0.014 0.00228 0.022 0.017 0.00224 0.026 0.020 0.00320 0.031 0.023 0.00318 0.034 0.026 0.00316 0.038 0.0
47、29 0.00414 0.044 0.033 0.00413 0.047 0.035 0.00512 0.051 0.038 0.00511 0.056 0.042 0.00610 0.061 0.046 0.0069 0.068 0.051 0.0078 0.077 0.058 0.0087 0.088 0.066 0.0096 0.102 0.077 0.010F835 13411. Test Methods11.1 Chemical analysis shall be conducted in accordance with Test Methods, Practices, and Te
48、rminology A751.11.2 Tensile properties shall be determined in accordance with Test Methods F606MF606.FIG. 1 Decarburization LimitsFIG. 2 Head and Body Discontinuity LimitationsFIG. 3 Socket Discontinuity LimitationsF835 13511.3 Hardness shall be determined in accordance with Test Methods E18.11.4 Em
49、brittlement tests shall be conducted in accordance with Test Methods F606MF606. The countersunk washer for the flatcountersunk head cap screw shall be placed with the axis except no wedge angle shall be used. The applied tension shall be axial.Tightening shall be applied using a zinc plated nut with a minimum proof strength of 150 000 psi tightened against a hardenedwasher and not by torque applied through the recess. For screws too short to perform a torque-tension test, tightening values shallbe calculated using the formula: Torque5KdP where K is 0.22 if
