ASTM F594-09 (Reapproved 2015)

Designation: F594 − 09 (Reapproved 2015)Standard Specification forStainless Steel Nuts1This standard is issued under the fixed designation F594; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of 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 requirements for stainlesssteel nuts 0.25 to 1.50 in., inclusive, in nominal diameter in anumber of alloys in common use and intended for serviceapplications requiring general corrosion resistance.1.2 Seven groups of stainless steel alloys are covered,including ten austenitic, two ferritic, four martensitic, and oneprecipitation hardening.Group AlloysAConditionB1 304, 305, 304L384, 18–9LW, 302HQC(CW) cold workedD2 316, 316L (CW) cold workedD3 321, 347 (CW) cold workedD4 430E(CW) cold workedD5 410F(H) hardened and tempered6 431 (H) hardened and tempered7 630 (AH) aged hardenedAUnless otherwise specified on the inquiry and order, the choice of an alloy fromwithin a group shall be at the discretion of the fastener manufacturer (see 6.1).BSee 4.2 for options.CWhen approved by the purchaser, alloys 303, 303Se, or XM1 may be furnished.DSizes 0.75 in. and larger may be hot worked and solution annealed.EWhen approved by the purchaser, alloy 430F may be furnished.FWhen approved by the purchaser, alloy 416 or 416Se may be furnished.1.3 Supplementary requirements of an optional nature areprovided, applicable only when agreed upon by the manufac-turer and the purchaser at the time of the inquiry and order.1.4 Suitable bolts, hex cap screws, and studs for use withnuts included in this specification are covered by SpecificationF593. Unless otherwise specified, all bolts, hex cap screws, andstuds used with these nuts shall conform to the requirements ofSpecification F593 and shall be of the same alloy group.1.5 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.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-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A262 Practices for Detecting Susceptibility to IntergranularAttack in Austenitic Stainless SteelsA342/A342M Test Methods for Permeability of WeaklyMagnetic MaterialsA380 Practice for Cleaning, Descaling, and Passivation ofStainless Steel Parts, Equipment, and SystemsA493 Specification for Stainless Steel Wire and Wire Rodsfor Cold Heading and Cold ForgingA555/A555M Specification for General Requirements forStainless Steel Wire and Wire RodsA564/A564M Specification for Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars and ShapesA582/A582M Specification for Free-Machining StainlessSteel BarsA751 Test Methods, Practices, and Terminology for Chemi-cal Analysis of Steel ProductsD3951 Practice for Commercial PackagingE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsF593 Specification for Stainless Steel Bolts, Hex CapScrews, and StudsF606 Test Methods for Determining the Mechanical Proper-ties of Externally and Internally Threaded Fasteners,Washers, and Rivets (Metric) F0606_F0606ME1470 Test Method for Characterization of Proteins byElectrophoretic Mobility (Withdrawn 2014)31This specification is under the jurisdiction of ASTM Committee F16 onFasteners and is the direct responsibility of Subcommittee F16.04 on NonferrousFasteners.Current edition approved Sept. 1, 2015. Published November 2015. Originallyapproved in 1978. Last previous edition approved in 2009 as F594 – 09ɛ1. DOI:10.1520/F0594-09R15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at service@astm.org. For Annual Book of ASTMStandards volume information, refer to the standard’s Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.*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 States12.2 ASME Standards:4B1.1 Unified Inch Screw ThreadsB18.2.2 Square and Hex NutsNOTE 1—The following ASTM standards are noted for informationonly as suitable sources of material for the manufacture of nuts to thisspecification:Specifications A493, A564/A564M, and A582/A582M.3. Ordering Information3.1 Orders for nuts under this specification shall include thefollowing:3.1.1 Quantity (number of pieces of each item and size),3.1.2 Name of item,3.1.3 Size (diameter and threads per inch),3.1.4 Alloy group number (see 6.2.1), and3.1.5 Condition (see 4.2).3.1.6 Orders for nuts under this specification may includethe following optional requirements:3.1.6.1 Forming (see 4.1.1),3.1.6.2 Composition (see 6.2),3.1.6.3 Corrosion resistance (see 8.1),3.1.6.4 Thread class (see 9.2),3.1.6.5 Finish (see 10.3),3.1.6.6 Test report (see 17.2),3.1.6.7 Rejection (see 16.1),3.1.6.8 Test rejection (see 16.1), and3.1.6.9 Special packaging (see 19.2).3.1.7 Supplementary requirements, if any, to be specified onthe order (see S1 through S8), and3.1.8 ASTM specification and date of issue. When date ofissue is not specified, fasteners shall be furnished to the latestissue.NOTE 2—Example: 10 000 pieces, Hex Nut, 0.250 in. −20,Alloy Group1, Condition CW, Furnish Test Report, Supplementary Requirement S3.4. Manufacture4.1 Manufacture:4.1.1 Forming—Unless otherwise specified, the nuts shallbe hot formed, cold formed, or machined from suitablematerial, at the option of the manufacturer.4.2 Condition—The fasteners shall be furnished in thefollowing conditions, unless specified to be furnished in one ofthe optional conditions:Alloy GroupCondition FurnishedUnless OtherwiseSpecifiedOptional Conditions(must be specified)1, 2, 3 CW AF, A, SH4C5HHT6H7 AH noneA— Machined from annealed or solution annealed stock thusretaining the properties of the original material; or hot formedand solution annealed.AF— Annealed after all threading is completed.AH— Solution annealed and age hardened after forming.CW— Annealed and cold worked. Sizes 0.75 in. and larger may behot worked and solution annealed.H— Hardened and tempered at 1050°F (565°C) minimum.HT— Hardened and tempered at 525°F (274°C) minimum.SH— Machined from strain hardened stock.5. Heat Treatment5.1 Alloy Groups 1, 2, and 3 (Austenitic Alloys 303, 303Se,304, 304L, 305, 316, 316L, 321, 347, 384, XM1, 18–9LW, and302HQ):5.1.1 Condition A—When Condition A is specified, theaustenitic alloys shall be heated to 1900 6 50°F (1038 628°C), at which time the chromium carbide will go into thesolution, be held for a sufficient time, and then be cooled at arate sufficient to prevent precipitation of the carbide and toprovide the specified properties.5.1.2 Condition CW—When Condition CW is specified, theaustenitic alloys shall be annealed as specified in 5.1.1 and thencold worked to develop the specified properties.5.1.3 Condition AF—When Condition AF is specified, theaustenitic alloys shall be annealed as specified in 5.1.1 after allcold working, including forming and threading.5.2 Alloy Group 4 (Ferritic Alloys 430 and 430F):5.2.1 Condition A—The ferritic alloys shall be heated to atemperature of 1450 6 50°F (788 6 28°C), held for anappropriate time, and then air cooled to provide the specifiedproperties.5.2.2 Condition CW—When Condition CW is specified, theferritic alloys shall be annealed in accordance with 5.2.1,generally by the raw material manufacturer, and then coldworked to develop the specified properties.5.3 Alloy Group 5 (Martensitic Alloys 410, 416, and 416Se):5.3.1 Condition H—When Condition H is specified, themartensitic alloys 410, 416, and 416Se shall be hardened andtempered by heating to 1850 6 50°F (1010 6 28°C) sufficientfor austenitization, held for at least1⁄2 h and rapid air- oroil-quenched, then reheating to 1050°F (565°C) minimum forat least 1 h and air cooled to provide the specified properties.5.3.2 Condition HT—When Condition HT is specified, themartensitic alloys 410, 416, and 416Se shall be hardened andtempered by heating to 1850 6 50°F (1010 6 28°C) sufficientfor austenitization, held for at least1⁄2 h and rapid air- oroil-quenched, then reheating to 525°F (274°C) minimum for atleast 1 h and air cooled to provide the specified properties.4Available from Global Engineering Documents, 15 Inverness Way, EastEnglewood, CO 80112-5704, http://www.global.ihs.comF594 − 09 (2015)25.4 Alloy Group 6 (Martensitic Alloy 431):5.4.1 Conditions H and HT—The martensitic alloy 431 shallbe hardened and tempered as specified in 5.3.1 and 5.3.2 asapplicable.5.5 Alloy Group 7 (Precipitation Hardening Alloy 630):5.5.1 Condition AH—The precipitation hardening alloy 630shall be solution annealed and aged by heating to 1900 6 25°F(1038 6 14°C) for at least1⁄2 h and rapid air or oil quenchedto 80°F (27°C) maximum, then reheating to a temperature of1150 6 15°F (621 6 8°C) for 4 h and air cooled to provide thespecified properties.6. Chemical Composition6.1 Alloy Groups—It is the intent of this specification thatfasteners shall be ordered by alloy group numbers that includealloys considered to be chemically equivalent for generalpurpose use. The alloy groupings are as shown below. Whenrequired, however, a specific alloy may be specified as permit-ted by 6.2.2.Alloy Group Alloys1 304, 305, 304L384, 18–9LW, 302HQA2 316, 316L3 321, 3474 430B5 410C6 4317 630AWhen approved by the purchaser, alloys 303, 303Se, or XM1 may be furnished.BWhen approved by the purchaser, alloy 430F may be furnished.CWhen approved by the purchaser, alloys 416 or 416Se may be furnished.6.2 Chemical Composition Limits:6.2.1 Ordering by Alloy Group—Unless otherwise specifiedon the inquiry and order (see Supplementary Requirement S4),the choice of an alloy from within a group shall be at thediscretion of the fastener manufacturer as required by hismethod of fastener fabrication and material availability. Thespecific alloy used by the fastener manufacturer shall be clearlyidentified on any certification required by the order and shallhave a chemical composition conforming to the requirementsof Table 1 for the specific alloy.6.2.2 Ordering by Specific Alloy—When ordered by a spe-cific alloy number, the fasteners shall conform to the chemicalcomposition limits of Table 1 for the specific alloy.6.3 Product Analysis:6.3.1 Product analysis may be made by the purchaser fromfinished nuts representing each lot. The chemical compositionthus determined shall conform to the requirements of Table 1for the specific alloy subject to the Product Analysis Tolerancein Specification A555/A555M.6.3.2 In the event of discrepancy, a referee chemical analy-sis of samples from each lot shall be made in accordance with14.1.7. Mechanical Properties7.1 The finished fasteners shall meet the applicable me-chanical properties of Table 2 for the specified alloy group andcondition when tested in accordance with the mechanicalproperty requirements as specified herein (see also Table 3).8. Corrosion Resistance8.1 Carbide Precipitation:8.1.1 Rod, bar, and wire in the austenitic Alloy Groups 1, 2,and 3, except the free-machining grades, 303 and 303Se usedto make fasteners in accordance with this specification, shall becapable of passing the test for susceptibility to intergranularcorrosion as specified in Practice E of Practice A262.8.1.2 As stated in Practice A262, samples may be subjectedto the faster and more severe screening test in accordance withPractice A. Failing Practice A, specimens may be tested inaccordance with Practice E and be considered satisfactory ifpassing Practice E.9. Dimensions9.1 Nuts:9.1.1 Unless otherwise specified, the dimensions shall be inaccordance with the requirements of ASME B18.2.2 for HexNuts.9.1.2 When specified, the dimensions of nuts shall be inaccordance with the requirements of ASME B18.2.2 (type asspecified), or such other dimensions as may be specified.9.2 Threads (see Table 4)—Unless otherwise specified, thenuts shall have Class 2B threads in accordance with ASMEB1.1.10. Workmanship, Finish, and Appearance10.1 Workmanship—The nuts shall have a workmanlikefinish, free of injurious burrs, seams, laps, irregular surfaces,and other defects affecting serviceability.10.2 Surface Finish—The nuts shall have a surface finishproduced in accordance with Practice A380.10.3 Protective Finishes—Unless otherwise specified, thenuts shall be furnished without an additive chemical or metallicfinish.11. Sampling11.1 Alot, for the purposes of selecting test specimens, shallconsist of not more than 100 000 pieces offered for inspectionat one time having the following common characteristics:11.1.1 One type of item,11.1.2 Same alloy and condition, and11.1.3 One nominal diameter and thread series.12. Number of Tests and Retests12.1 Number of Tests:12.1.1 Mechanical Tests—The mechanical requirements ofthis specification shall be met in continuous mass productionfor stock. The manufacturer shall make sample inspections asspecified below to ensure the product conforms to the specifiedrequirements. When tests of individual shipments are required,Supplementary Requirement S1 must be specified in theinquiry and order.Acceptance CriteriaNumber of Pieces in Lot Numberof TestsAcceptanceNumberRejectionNumber2to50 2 0 151 to 500 3 0 1501 to 35 000 5 0 135 001 to 100 000 8 0 1F594 − 09 (2015)312.1.2 Corrosion Resistance Tests:12.1.2.1 Unless otherwise specified, tests for corrosion re-sistance shall be in accordance with the manufacturer’s stan-dard quality control practices. A specific number of tests is notrequired, but the fasteners shall be produced by manufacturingpractices and subjected to tests and inspection to assurecompliance with the specified requirements.12.1.2.2 When specified on the purchase order, not less thanone corrosion test to determine freedom from precipitatedcarbides shall be made to represent each lot.12.2 Retests:12.2.1 When tested in accordance with the required sam-pling plan, a lot shall be subject to rejection if any of the testspecimens fail to meet the applicable test requirements.12.2.2 If the failure of a test specimen is due to improperpreparation of the specimen or to incorrect testing technique,the specimen shall be discarded and another specimen substi-tuted.13. Specimen Preparation13.1 Chemical Tests—When required, samples for chemicalanalysis shall be taken by drilling, sawing, milling, turning,clipping, or other suc