1、Designation: F 812/F 812M 07Standard Specification forSurface Discontinuities of Nuts, Inch and Metric Series1This standard is issued under the fixed designation F 812/F 812M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the yea
2、r of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon (e) 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 establishes
3、 allowable limits for thevarious types of surface discontinuities that may occur duringthe manufacture and processing of metric-series nuts withnominal diameters 5 mm and larger and inch-series nuts withnominal diameters14 in. and larger.1.2 The values stated in either SI (metric) or inch-poundunits
4、 are to be regarded separately as standard. The valuesstated in each system are not exact equivalents; therefore, eachsystem must be used independently of the other. Combiningvalues from the two systems may result in nonconformancewith the specification.1.3 When the engineering requirements of the a
5、pplicationnecessitate control of surface discontinuities on nuts, thepurchaser shall specify conformance to this ASTM specifica-tion in the original inquiry and purchase order.1.3.1 When the engineering requirements of the applicationnecessitate that surface discontinuities on nuts be controlledwith
6、in limits closer than those specified in this specification,the purchaser shall specify the applicable limits in the originalinquiry and purchase order.1.4 The allowable limits established in this specification formetric nuts, with nominal diameters 5 to 24 mm inclusive, areessentially identical wit
7、h requirements given in ISO/DIS 6157/II. There are no ISO standards for surface discontinuities onmetric-series nuts with nominal diameters larger than 24 mm oron any inch-series nuts.1.5 The following precautionary caveat pertains only to thetest method portion, Section 7, of this specification: Th
8、isstandard 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 Documents2
9、.1 ASTM Standards:2F 606 Test Methods for Determining the Mechanical Prop-erties of Externally and Internally Threaded Fasteners,Washers, Direct Tension Indicators, and RivetsF 606M Test Methods for Determining the MechanicalProperties of Externally and Internally Threaded Fasteners,Washers, and Riv
10、ets MetricF 1470 Guide for Fastener Sampling for Specified Mechani-cal Properties and Performance InspectionF 1789 Terminology for F16 Mechanical Fasteners2.2 ISO Standard:ISO/DIS 6157/II Fasteners, Surface Discontinuities onNuts33. Ordering Information3.1 Orders for nuts requiring surface discontin
11、uity controlshall include:3.1.1 ASTM designation and date of issue of this specifica-tion.3.1.2 Special requirements, for example, closer discontinu-ity limits (1.3.1) and inspection sampling plan (6.2).4. Types of Surface Discontinuities (See Standard F 1789for definitions not provided)4.1 Crack:4.
12、1.1 Quench CracksTypical quench cracks are shown inFig. 1; limits are specified in 5.2.4.1.2 Forging CracksTypical forging cracks are shown inFig. 2; limits are specified in 5.3.4.1.3 Inclusion CracksNormally caused by nonmetallicinclusions or stringers inherent in the raw material. Typicalinclusion
13、 cracks are shown in Fig. 2; limits are specified in 5.3.1This specification is under the jurisdiction of ASTM Committee F16 onFasteners and is the direct responsibility of Subcommittee F16.93 on QualityAssurance Provisions for Fasteners.Current edition approved Nov. 15, 2007. Published December 200
14、7. Originallyapproved in 1983. Last previous edition approved in 2003 as F 812/F 812M 03.2For referenced ASTM standards, 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 Summ
15、ary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.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 Conshoh
16、ocken, PA 19428-2959, United States.4.1.4 Locking-Element CracksOccur due to application ofpressure when forming the locking element of prevailingtorque-type nuts. Such cracks are usually located in the vicinityof the locking element and may be either on the internal orexternal surface. Typical lock
17、ing element cracks are shown inFig. 3; limits are specified in 5.4.4.1.5 Washer-Retainer CracksOpenings in the lip or hubof metal used to retain a washer on a nut. Washer-retainercracks may occur when pressure is applied to the lip or hubduring assembly of the washer. Typical washer-retainer cracksa
18、re shown in Fig. 4; limits are specified in 5.5.4.2 BurstA typical burst is shown in Fig. 5; limits arespecified in 5.6.4.2.1 Shear BurstA typical shear burst is shown in Fig. 5;limits are specified in 5.6.4.3 SeamTypical seams are shown in Fig. 6; limits arespecified in 5.7.4.4 FoldTypical folds ar
19、e shown in Fig. 7; limits arespecified in 5.8.4.5 VoidVoids are produced by marks or impressions ofchips (shear burrs) or by rust formation on the raw material.They are not planished during forging. Typical voids are shownin Fig. 8; limits are specified in 5.9.4.6 Tool MarksTypical tool marks are sh
20、own in Fig. 9;limits are specified in 5.10.FIG. 1 Typical Quench Cracks in NutsFIG. 2 Typical Forging and Inclusion Cracks in NutsFIG. 3 Typical Locking Element Cracks in Prevailing-Torque NutsFIG. 4 Typical Washer Retainer Cracks in NutsFIG. 5 Typical Bursts and Shear Bursts in NutsFIG. 6 Typical S
21、eams in NutsF 812/F 812M 0724.7 Gouge and Nickan indentation on the surface of afastener produced by impact with another fastener, or fromprocessing equipment during manufacture, handling, or trans-port.5. Allowable Limits5.1 Letter DefinitionsThroughout the following require-ments, D designates the
22、 nominal nut size (basic major diameterof thread); Dc designates flange diameter (specified maximum)on flanged nuts; S designates nominal (specified maximum)width across flats. For metric-series nuts, D, Dc, and S are inmillimetres; for inch series nuts, D, Dc, and S are in inches.5.2 Quench CracksQ
23、uench cracks of any depth, anylength, or in any location are not permitted.5.3 Forging Cracks and Inclusion CracksForging andinclusion cracks located in the top and bottom faces of nuts ofall sizes are permitted provided that ( a) there are not more thantwo cracks that extend from the tapped hole ac
24、ross the fullwidth of the face; (b) no crack extends into the tapped holebeyond the first full thread; (c) no crack in the threads exceedsa depth of 0.5 times the thread height; and (d) the width of anycrack does not exceed 0.02 D or 0.30 mm or 0.012 in.,whichever is greater.5.3.1 Additionally, hex
25、nuts with nominal diameters 5 to 36mm inclusive and14 to 112 in. inclusive, showing discontinuityindications, shall meet the requirements of the cone proof loadtest when sampled in accordance with 6.1, using samplesselected in accordance with 6.5.2.5.4 Locking Element Cracks:5.4.1 Locking-element cr
26、acks (or seams) located on theexternal surface of the locking element of prevailing torquenuts are permitted provided that the net meets all applicabletorque requirements.5.4.1.1 Additionally, hex nuts with nominal diameters 5 to36 mm inclusive and14 to 112 in. inclusive, showing discon-tinuity indi
27、cations, shall meet the requirements of the coneFIG. 7 Typical Folds on Surfaces of NutsFIG. 8 Typical Voids in NutsFIG. 9 Typical Tool Marks on Nut SurfaceF 812/F 812M 073proof load test when sampled in accordance with 6.1, usingsamples selected in accordance with 6.5.2.5.4.2 Locking-element cracks
28、 located on the internal sur-face (threaded or unthreaded) of prevailing torque nuts arepermitted provided that (a) no crack exceeds a length of twothread pitches; (b) no crack shall extend into the thread root;and (c) no crack shall have a width exceeding the following:5.4.2.1 Metric-Series Nuts0.1
29、8 mm for nuts with nominaldiameters 5 to 10 mm inclusive, 0.25 mm for nuts with nominaldiameters over 10 to 24 mm inclusive, and 0.40 mm for nutswith nominal diameters larger than 24 mm.5.4.2.2 Inch Series Nuts0.007 in. for nuts with nominaldiameters14 to716 in. inclusive, 0.010 in. for nuts withnom
30、inal diameters over716 to 1 in. inclusive, and 0.016 in. fornuts with nominal diameters larger than 1 in.5.5 Washer-Retainer CracksWasher-retainer cracks arepermitted if their location is limited to the contour of the lip orhub used for retaining purposes.5.6 Bursts and Shear Bursts:5.6.1 For hex nu
31、ts, bursts and shear bursts are permittedprovided that (a) no burst or shear burst in the flats extends intothe crown (chamfer) circle on the top of the nut or into thebearing circle on the bottom face; (b) no burst or shear burstlocated at the intersection of the top or bottom face with awrenching
32、flat has a width greater than 0.25 mm or 0.010 in.plus 0.02 S; and (c) no burst occurring at the intersection of twowrenching flats reduces the width across corners below itsspecified minimum.5.6.2 For flanged nuts, bursts and shear bursts at theperiphery of the flange are permitted provided that (a
33、) not morethan one of the bursts or shear bursts has a width greater than0.04 Dc , and (b) the width of the one burst or shear burst thatexceeds a width of 0.04 Dc does not have a width greater than0.08 Dc.5.7 SeamsSeams are permitted provided that no seam hasan open width at the surface greater tha
34、n 0.013 D for nuts withnominal diameters 5 to 6 mm inclusive; 0.02 D for metric nutswith nominal diameters larger than 6 mm; and 0.02 D for allsizes of inch-series nuts.5.7.1 Additionally, hex nuts with nominal diameters 5 to 36mm inclusive and14 to 112 in. inclusive, showing discontinuityindication
35、s, shall meet the requirements of the cone proof loadtest when sampled in accordance with 6.1 using samplesselected in accordance with 6.5.2.5.8 FoldsFolds located at the intersection of the flangeperiphery and bearing surface of flanged nuts shall not projectbelow the bearing surface. All other fol
36、ds on nuts are permit-ted.5.9 Voids:5.9.1 Voids on the surfaces of nuts are permitted providedthat (a) depth of voids does not exceed 0.25 mm or 0.010 in. or0.02 D, whichever is greater, and (b) the combined area of allvoids on the bearing surface does not exceed 10% of thespecified minimum-bearing
37、surface area.5.9.2 The method for determining the area of voids on thebearing surface shall be as agreed upon by purchaser andproducer.5.10 Tool Marks:5.10.1 Tool marks on the bearing surface are permittedprovided the surface roughness measurement does not exceed3.2 m or 125 in., determined as the a
38、rithmetic averagedeviation from the mean surface.5.10.2 Tool marks on other surfaces of the nut are permitted.5.11 Nicks and GougesNicks, gouges, dents, and scrapesare permitted provided that the functionality of the nut is notimpaired.6. Inspection and Evaluation6.1 Nuts shall be inspected for surf
39、ace discontinuities inaccordance with the procedures in 6.2, 6.3, and 6.4.6.2 The purchaser shall specify in the original inquiry andpurchase order the inspection sampling requirements which theproducer must satisfy to demonstrate the acceptability of nutswith respect to surface discontinuities.6.3
40、In the absence of purchaser instructions (6.2), inspectionand evaluation shall be in accordance with 6.5.6.4 For referee purposes, unless other procedures have beenspecified by the purchaser (6.2), inspection and evaluation shallbe in accordance with 6.5.6.5 Inspection Procedure:6.5.1 Visual Inspect
41、ion:6.5.1.1 A random sample shall be taken from the lot inaccordance with Guide F 1470, and examined visually for thepresence of quench cracks, forging cracks, inclusion cracks,locking-element cracks, washer retainer cracks, bursts, shearbursts, seams, folds, voids, tool marks, and nicks and gouges.
42、6.5.1.2 If during this inspection any nuts with quench cracksare found, the lot may be rejected by the purchaser.6.5.1.3 If during this inspection any nuts are found with anyother surface discontinuity, each discontinuity shall be mea-sured and if any is found that exceeds the allowable dimen-sional
43、 limits for that discontinuity as specified in Section 5, thelot may be rejected by the purchaser.6.5.1.4 Measurement of Surface Discontinuities in Nuts:(1) For discontinuities originating from a flat: at the extrem-ity of the discontinuity measure distance D perpendicular to theflat where the disco
44、ntinuity originated (see Fig. 10).FIG. 10 Measurement of Surface DiscontinuitiesF 812/F 812M 074(2) For discontinuities originating from a corner: at theextremity of the discontinuity measure distance D in a straightline to the corner where the discontinuity originated (see Fig.10).6.5.2 Mechanical
45、TestingDuring the visual inspection, allhex nuts with nominal diameters 5 to 36 mm inclusive and14to 112 in. inclusive, that have indications of forging cracks,inclusion cracks, locking-element cracks on external surfaces,or seams, shall be set aside. From this lot, a sample of size inaccordance wit
46、h Guide F 1470, and consisting of those nutsindicating the most serious defects, shall be cone proof loadtested as specified in 7.1. If any nut fails to meet therequirements of this test, the lot may be rejected by thepurchaser.7. Test Method7.1 Cone Proof Load TestIf required in 6.5.2, the coneproo
47、f load test shall be conducted in accordance with the ConeProof Load Test Methods F 606 (Inch products), or F 606M(Metric products).8. Keywords8.1 Crack; Discontinuities (Surface); Fold; Nut; Seam;Void.SUMMARY OF CHANGESCommittee F16 has identified the location of selected changes to this standard s
48、ince the last issueF 812/F 812M-03 that may impact the use of this standard.(1) 4.7 was revised.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determin
49、ation of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technica
