ASME B18.2.2:2022 pdf download

ASME B18.2.2:2022 pdf download.Nuts for General Applications: Machine Screw Nuts; and Hex, Square, Hex Flange, and Coupling Nuts (Inch Series)
1 INTRODUCTION
1.1 Scope 1.1.1 This Standard is intended to coverthe complete general and dimensional data forthe types ofinch series square and hex nuts, including machine screw nuts and coupling nuts (see Tables 1.1.1-1 through 1.1.1-15). Also included are appendices covering gaging ofslots in slotted nuts, wrench openings for nuts, formulas on which dimensional data are based, and measurement of bearing surface runout. It should be understood that where questions arise concerning acceptance of product, the dimensions in the tables shall govern over recalculation by formula. 1.1.2 The inclusion of dimensional data in this Standard is not intended to imply that all of the products described herein are stock production sizes. Consumers are requested to consult with manufacturers concerning lists of stock production sizes. 1.2 Comparison to ISO Standards There are no comparable ISO inch fastener standards. 1.3 Dimensions Unless otherwise indicated, units of measurement are expressed in inches. 1.4 Options Where options are allowed, they shall be selected at the manufacturer’s discretion unless otherwise specified by the purchaser. 1.5 Terminology References For definitions of terminology not specifically defined in this Standard, refer to ASME B18.12.
3 GENERAL DATA
3.1 Width Across Flats The width across flats of nut shall be the overall distance measured, perpendicular to the axis of nut, between two opposite sides of the nut in accordance with the notes on respective dimensional tables. Maximum width across flats shall not be exceeded, except as stated below. No transverse section through the nut between 25% and 75% ofthe actual nutthickness as measured from the bearing surface shall be less than the minimum width across flats. NOTE: Nonferrousmilled-from-barhexnuts: Theminimumacrossflatsdimensionsofnonferrousmilled-from-barhexnutsshallnotbe less than the values tabulated in Tables 1.1.1-1 through 1.1.1-15. The maximum across flats size may be greater than the tabulated values in Tables 1.1.1-1 through 1.1.1-15 but shall not be equal to or greater than the minimum wrench opening shown in Nonmandatory Appendix B, Table B-1,providedthewidthacrosscorners is within specified limits at and beyond a distance equal to 17.5% ofthe basic thread diameter from the chamfered face. 3.3 Tops of Nuts and Chamfers Topsofnutsshallbeflatandchamfered,exceptcastlenutswherechamferis optional.nuts ofnominal size 5 ∕ 8 in. and smallershall be double-chamfered. Largersize nuts shall be double-chamfered or have washer-faced bearing surface and chamfered top. 3.3.1 Single-Chamfered Nuts and Washer-Faced Nuts. Diameterofthe chamfercircle shall be equal to the maximum width across flats within a tolerance of−15%. The length ofchamfer athex corners shall be from 5% to 15% ofthe basic thread diameter. The surface of the chamfer may be slightly convex or rounded. 3.3.2 Double-Chamfered Nuts. Diameterofthechamfercircle shall be equal to themaximumwidth across flats witha −10% tolerance.3.4 Countersink Unless otherwise specified in this Standard, tapped holes shall be countersunk on the bearing faces. The maximum countersink diameter shall be the thread basic (nominal) major diameter plus 0.030 in. for nuts of nominal size 3 ∕ 8 in. and smaller, and 1.08 times the basic major diameter for nuts larger than 3 ∕ 8 in. No part of the threaded portion shall project beyond the bearing surface. 3.5 Nut Thickness Thenutthicknessshallbetheoveralldistance,measuredparalleltotheaxisofnut,fromthetop ofthenuttothebearing surface and shall include the thickness of the washer face where provided. 3.6 Washer Face Diameter Unlessotherwisespecified,theoutsidediameterofwasherfaceshallbeequalto the maximumwidthacross flats witha −10% tolerance. 3.7 Slots Whenspecified in the respective dimensional table, slots shall be normal to nutflats. The contourofthe bottom ofslots shall be at manufacturer’s option. Requirements for gaging slots are specified in Mandatory Appendix I.3.8.2 SquareNuts. Theaxis oftappedholeinsquarenuts shallbelocatedattruepositionwithrespecttotheaxis ofnut body within a tolerance zone having a diameter equivalent to 10% of the maximum width across flats, regardless of feature size. 3.9 Bearing Surface Perpendicularity Bearing surface shall be flat and perpendicular to the axis of the threaded hole within the specified full indicator measurement (FIM) limit indicated in the tables. See Nonmandatory Appendix C for measurement procedure.