1、Designation: F812/F812M 07 F812 12Standard Specification forSurface Discontinuities of Nuts, Inch and Metric Series1This standard is issued under the fixed designation F812/F812M;F812; the number immediately following the designation indicates theyear of original adoption or, in the case of revision
2、, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () 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 est
3、ablishes allowable limits for the various types of surface discontinuities that may occur during themanufacture and processing of metric-series nuts with nominal diameters 5 mm and larger and inch-series nuts with nominaldiameters 14 in. and larger.1.2 The values stated in either SI (metric) or inch
4、-pound units are to be regarded separately as standard. The values stated ineach system are not exact equivalents; therefore, each system must be used independently of the other. Combining values fromthe two systems may result in nonconformance with the specification.1.3 When the engineering require
5、ments of the application necessitate control of surface discontinuities on nuts, the purchasershall specify conformance to this ASTM specification in the original inquiry and purchase order.1.3.1 When the engineering requirements of the application necessitate that surface discontinuities on nuts be
6、 controlled withinlimits closer than those specified in this specification, the purchaser shall specify the applicable limits in the original inquiry andpurchase order.1.4 The allowable limits established in this specification for metric nuts, with nominal diameters 5 to 24 mm inclusive, areessentia
7、lly identical with 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 or on any inch-series nuts.1.5 The following precautionary caveat pertains only to the test method portion, Section 7, of thi
8、s specification:This standarddoes not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of thisstandard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.2. Re
9、ferenced Documents2.1 ASTM Standards:2F606 Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, DirectTension Indicators, and RivetsF606M Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners
10、, Washers, andRivets (Metric)F1470 Practice for Fastener Sampling for Specified Mechanical Properties and Performance InspectionF1789 Terminology for F16 Mechanical Fasteners2.2 ISO Standard:ISO/DIS 6157/II Fasteners, Surface Discontinuities on Nuts33. Ordering Information3.1 Orders for nuts requiri
11、ng surface discontinuity control shall include:3.1.1 ASTM designation and date of issue of this specification.3.1.2 Special requirements, for example, closer discontinuity limits (1.3.1) and inspection sampling plan (6.2).4. Types of Surface Discontinuities (See Standard F1789 for definitions not pr
12、ovided)4.1 Crack:4.1.1 Quench CracksTypical quench cracks are shown in Fig. 1; limits are specified in 5.2.4.1.2 Forging CracksTypical forging cracks are shown in Fig. 2; limits are specified in 5.3.4.1.3 Inclusion CracksNormally caused by nonmetallic inclusions or stringers inherent in the raw mate
13、rial. Typical inclusioncracks are shown in Fig. 2; limits are specified in 5.3.*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 States14.1.4 Locking-Element CracksOccur due to a
14、pplication of pressure when forming the locking element of prevailingtorque-type nuts. Such cracks are usually located in the vicinity of the locking element and may be either on the internal or externalsurface. Typical locking element cracks are shown in Fig. 3; limits are specified in 5.4.4.1.5 Wa
15、sher-Retainer CracksOpenings in the lip or hub of metal used to retain a washer on a nut. Washer-retainer cracks mayoccur when pressure is applied to the lip or hub during assembly of the washer. Typical washer-retainer cracks are shown in Fig.4; limits are specified in 5.5.4.2 BurstA typical burst
16、is shown in Fig. 5; limits are specified 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 are specified in 5.7.4.4 FoldTypical folds are shown in Fig. 7; limits are specified in 5.8.4.5 VoidVoids are produ
17、ced by marks or impressions of chips (shear burrs) or by rust formation on the raw material. Theyare not planished during forging. Typical voids are shown in Fig. 8; limits are specified in 5.9.1 This specification is under the jurisdiction of ASTM Committee F16 on Fasteners and is the direct respon
18、sibility of Subcommittee F16.93 on Quality AssuranceProvisions for Fasteners.Current edition approved Nov. 15, 2007Oct. 1, 2012. Published December 2007November 2012. Originally approved in 1983. Last previous edition approved in 20032007as F812/F812M 03.F812/F812M 07. DOI: 10.1520/F0812_F0812M-07.1
19、0.1520/F0812-12.2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM 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 American National Standar
20、ds Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.FIG. 1 Typical Quench Cracks in NutsFIG. 2 Typical Forging and Inclusion Cracks in NutsFIG. 3 Typical Locking Element Cracks in Prevailing-Torque NutsF812 1224.6 Tool MarksTypical tool marks are shown in Fig. 9; l
21、imits are specified in 5.10.4.7 Gouge and Nickan indentation on the surface of a fastener produced by impact with another fastener, or from processingequipment during manufacture, handling, or transport.5. Allowable Limits5.1 Letter DefinitionsThroughout the following requirements, D designates the
22、nominal nut size (basic major diameter ofthread); Dc designates flange diameter (specified maximum) on flanged nuts; S designates nominal (specified maximum) widthacross flats. For metric-series nuts, D,Dc, and S are in millimetres; for inch series nuts, D,Dc, and S are in inches.5.2 Quench CracksQu
23、ench cracks of any depth, any length, or in any location are not permitted.5.3 Forging Cracks and Inclusion CracksForging and inclusion cracks located in the top and bottom faces of nuts of all sizesare permitted provided that (a) there are not more than two cracks that extend from the tapped hole a
24、cross the full width of theface; (b) no crack extends into the tapped hole beyond the first full thread; (c) no crack in the threads exceeds a depth of 0.5 timesthe thread height; and (d) the width of any crack does not exceed 0.02 D or 0.30 mm or 0.012 in., whichever is greater.5.3.1 Additionally,
25、hex nuts with nominal diameters 5 to 36 mm inclusive and 14 to 112 in. inclusive, showing discontinuityindications, shall meet the requirements of the cone proof load test when sampled in accordance with 6.1, using samples selectedin accordance with 6.5.2.5.4 Locking Element Cracks:FIG. 4 Typical Wa
26、sher Retainer Cracks in NutsFIG. 5 Typical Bursts and Shear Bursts in NutsFIG. 6 Typical Seams in NutsF812 1235.4.1 Locking-element cracks (or seams) located on the external surface of the locking element of prevailing torque nuts arepermitted provided that the net meets all applicable torque requir
27、ements.5.4.1.1 Additionally, hex nuts with nominal diameters 5 to 36 mm inclusive and 14 to 112 in. inclusive, showing discontinuityindications, shall meet the requirements of the cone proof load test when sampled in accordance with 6.1, using samples selectedin accordance with 6.5.2.5.4.2 Locking-e
28、lement cracks located on the internal surface (threaded or unthreaded) of prevailing torque nuts are permittedprovided that (a) no crack exceeds a length of two thread pitches; (b) no crack shall extend into the thread root; and (c) no crackshall have a width exceeding the following:FIG. 7 Typical F
29、olds on Surfaces of NutsFIG. 8 Typical Voids in NutsFIG. 9 Typical Tool Marks on Nut SurfaceF812 1245.4.2.1 Metric-Series Nuts0.18 mm for nuts with nominal diameters 5 to 10 mm inclusive, 0.25 mm for nuts with nominaldiameters over 10 to 24 mm inclusive, and 0.40 mm for nuts with nominal diameters l
30、arger than 24 mm.5.4.2.2 Inch Series Nuts0.007 in. for nuts with nominal diameters 14 to 716 in. inclusive, 0.010 in. for nuts with nominaldiameters over 716 to 1 in. inclusive, and 0.016 in. for nuts with nominal diameters larger than 1 in.5.5 Washer-Retainer CracksWasher-retainer cracks are permit
31、ted if their location is limited to the contour of the lip or hubused for retaining purposes.5.6 Bursts and Shear Bursts:5.6.1 For hex nuts, bursts and shear bursts are permitted provided that (a) no burst or shear burst in the flats extends into thecrown (chamfer) circle on the top of the nut or in
32、to the bearing circle on the bottom face; (b) no burst or shear burst located atthe intersection of the top or bottom face with a wrenching 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 two wrenching flats reduces the width across co
33、rners below its specified minimum.5.6.2 For flanged nuts, bursts and shear bursts at the periphery of the flange are permitted provided that (a) not more than oneof the bursts or shear bursts has a width greater than 0.04 Dc, and (b) the width of the one burst or shear burst that exceeds a widthof 0
34、.04 Dc does not have a width greater than 0.08 Dc.5.7 SeamsSeams are permitted provided that no seam has an open width at the surface greater than 0.013 D for nuts withnominal diameters 5 to 6 mm inclusive; 0.02 D for metric nuts with nominal diameters larger than 6 mm; and 0.02 D for all sizesof in
35、ch-series nuts.5.7.1 Additionally, hex nuts with nominal diameters 5 to 36 mm inclusive and 14 to 112 in. inclusive, showing discontinuityindications, shall meet the requirements of the cone proof load test when sampled in accordance with 6.1 using samples selectedin accordance with 6.5.2.5.8 FoldsF
36、olds located at the intersection of the flange periphery and bearing surface of flanged nuts shall not project belowthe bearing surface. All other folds on nuts are permitted.5.9 Voids:5.9.1 Voids on the surfaces of nuts are permitted provided that (a) depth of voids does not exceed 0.25 mm or 0.010
37、 in. or 0.02D, whichever is greater, and (b) the combined area of all voids on the bearing surface does not exceed 10% of the specifiedminimum-bearing surface area.5.9.2 The method for determining the area of voids on the bearing surface shall be as agreed upon by purchaser and producer.5.10 Tool Ma
38、rks:5.10.1 Tool marks on the bearing surface are permitted provided the surface roughness measurement does not exceed 3.2 mor 125 in., determined as the arithmetic average deviation from the mean surface.5.10.2 Tool marks on other surfaces of the nut are permitted.5.11 Nicks and GougesNicks, gouges,
39、 dents, and scrapes are permitted provided that the functionality of the nut is notimpaired.6. Inspection and Evaluation6.1 Nuts shall be inspected for surface discontinuities in accordance with the procedures in 6.2, 6.3, and 6.4.6.2 The purchaser shall specify in the original inquiry and purchase
40、order the inspection sampling requirements which theproducer must satisfy to demonstrate the acceptability of nuts with respect to surface discontinuities.6.3 In the absence of purchaser instructions (6.2), inspection and evaluation shall be in accordance with 6.5.6.4 For referee purposes, unless ot
41、her procedures have been specified by the purchaser (6.2), inspection and evaluation shall bein accordance with 6.5.6.5 Inspection Procedure:6.5.1 Visual Inspection:6.5.1.1 A random sample shall be taken from the lot in accordance with Guide F1470, and examined visually for the presenceof quench cra
42、cks, forging cracks, inclusion cracks, locking-element cracks, washer retainer cracks, bursts, shear bursts, seams,folds, voids, tool marks, and nicks and gouges.6.5.1.2 If during this inspection any nuts with quench cracks are found, the lot may be rejected by the purchaser.6.5.1.3 If during this i
43、nspection any nuts are found with any other surface discontinuity, each discontinuity shall be measuredand if any is found that exceeds the allowable dimensional limits for that discontinuity as specified in Section 5, the lot may berejected by the purchaser.6.5.1.4 Measurement of Surface Discontinu
44、ities in Nuts: (1) For discontinuities originating from a flat: at the extremity of thediscontinuity measure distance D perpendicular to the flat where the discontinuity originated (see Fig. 10).(2) For discontinuities originating from a corner: at the extremity of the discontinuity measure distance
45、 D in a straight line tothe corner where the discontinuity originated (see Fig. 10).F812 1256.5.2 Mechanical TestingDuring the visual inspection, all hex nuts with nominal diameters 5 to 36 mm inclusive and 14 to112 in. inclusive, that have indications of forging cracks, inclusion cracks, locking-el
46、ement cracks on external surfaces, or seams,shall be set aside. From this lot, a sample of size in accordance with Guide F1470, and consisting of those nuts indicating the mostserious defects, shall be cone proof load tested as specified in 7.1. If any nut fails to meet the requirements of this test
47、, the lot maybe rejected by the purchaser.7. Test Method7.1 Cone Proof Load TestIf required in 6.5.2, the cone proof load test shall be conducted in accordance with the Cone ProofLoad Test Methods F606 (Inch products), or F606M (Metric products).8. Keywords8.1 Crack; Discontinuities (Surface); Fold;
48、 Nut; Seam; Void.SUMMARY OF CHANGESCommittee F16 has identified the location of selected changes to this standard since the last issueF812/F812M-03-07 that may impact the use of this standard.(1) 4.7 was revised./812M was removed from the designation.ASTM International takes no position respecting t
49、he validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination 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 addition
