1、 No part of this translation may be reproduced without the prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).English price group 5 www.din.de www.beuth.de02.05 9609551Document
2、 comprises 3 pages.ICS 21.060.10Kombi-Schrauben mit Regelgewinde Teil 5: Mit SpannscheibeIn keeping with current practice in standards published by the International Organization for Standardization (ISO), a comma has been used throughout as the decimal marker.6900-5Screw and washer assembliesPart 5
3、 Assemblies with coarse threaded screws and captive conical spring washerTranslation by DIN-Sprachendienst.In case of doubt, the German-language original should be consulted as the authoritative text.Supersedes December 1990 edition.DEUTSCHE NORM September 2004!,_V“ForewordThis standard has been pr
4、epared by the Normenausschuss Mechanische Verbindungselemente (Fasteners Standards Committee), Technical Committee Kombi-Schrauben.AmendmentsThis standard differs from the December 1990 edition, as follows:a) Specications of the underhead llet radius have been dropped.b) The underhead llet diameter,
5、 da, is no longer specied.c) The washer height has been harmonized with the specications of DIN 6908.d) References have been updated.Previous editionsDIN 6900: 1966-09, 1972-12; DIN 6900-5: 1990-12.All dimensions are in millimetres.1 ScopeThis standard species requirements for screw and washer assem
6、blies consisting of an M2,5 to M12 screw with coarse thread and at bearing face, assigned to property classes 8.8 up to and including 10.9, and a captive conical spring washer. Spring washers are intended to counteract loosening of bolted connections (e.g. as a result of setting) (cf. DIN 267-26). T
7、hey do not effectively prevent loosening of the connection under varying radial load and are thus designed for use with short screws predominantly subject to thrust.Socket or cross recessed head screws the critical cross section of which is not located in the threaded por-tion of the shank but in th
8、e head are not suitable for screw and washer assemblies. For further restrictions in the use of such screws, see the relevant product standards.2 Normative referencesThis standard incorporates, by dated or undated reference, provisions from other publications. These normative references are cited at
9、 the appropriate places in the text and the titles of the publications are listed below. For dated references, subsequent amendments to or revisions of any of these publications apply to this standard only when incorporated in it by amendment or revision. For undated references, the latest edition o
10、f the publication referred to applies.DIN 267-26 Fasteners Technical delivery conditions Steel spring washers for bolt/nut assem-blies *)DIN 6900-1 Screw and washer assemblies Coarse threaded screws with captive plain washerDIN 6908 Conical spring washers for screw and washer assembliesDIN 34821 Che
11、ese head screws with internal serrations *)DIN EN ISO 898-1 Mechanical properties of fasteners made of carbon steel and alloy steel Part 1: Bolts, screws and studs (ISO 898-1 : 1999)*) Currently at draft stage.Page 2DIN 6900-5 : 2004-093 ConceptSee DIN 6900-1 for denition of screw and washer assembl
12、y.4 DimensionsOnly screws with a shank diameter approximately equal to the pitch diameter or threaded up to the head may be used for assemblies as specied in here.In order to obtain diameter da1as in gure 1 (see table 1), the underhead llet diameter, da, as specied in the relevant product standards,
13、 shall be smaller by an amount equal to the difference between nominal thread diam-eter and pitch diameter, without this changing the underhead llet radius specied in the product standard.Figure 1: Underhead llet diameter and shank diameter (notation)Washers shall conform to DIN 6908. See table 1 an
14、d gures 2 and 3 for some major dimensions of screw and washer assemblies and the relevant product standard for other dimensions.Examples of screw and washer assembliesFigure 2: Assembly with screw threaded approximately up to the headFigure 3: Assembly with screw with unthreaded portion of shankTabl
15、e 1: Major dimensions of screw and washer assembliesThread size (d)a da1l2 min1)Maximum washer dimensions 2)Max. Max. Nominal size h d2M2,5 0,9 2,8 4 2,25 0,72 6M3 1 3,3 4 2,75 0,85 7(M3,5) *) 1,2 3,7 6 3,2 1,06 8M4 1,4 4,3 6 3,6 1,3 9M5 1,6 5,2 6 4,55 1,55 11M6 2 6,2 8 5,5 2,6 14M8 2,5 8,4 10 7,4 3
16、1 18M10 3 10,2 12 9,3 3,6 23M12 3,5 12,6 14 11 4,1 29*) Use of the size given in brackets should be avoided.1) l2 minis the smallest effective screw length manufacturable.2) Washer as in DIN 6908, August1995 edition.See relevant product standards for specications for l.Page 3DIN 6900-5 : 2004-095 T
17、echnical delivery conditionsScrews and washers used to make assemblies shall comply with the relevant technical delivery conditions except that, as a deviation from DIN EN ISO 898-1, tensile strength and strength under wedge loading are to be tested on the assembly, not on its components.6 Designati
18、onThe designation of a screw and washer assembly is to include the name of the screw, letter Z to denote that the screw is tted with a captive washer and code number 9 denoting the conical spring washer.EXAMPLE:Designation of a DIN 34821 M6 20 8.8 type cheese head screw tted with DIN 6908 5,5 FSt type washer (Z9):Screw and washer assembly DIN 34821 M6 20 Z9 8.8
