1、DEUTSCHE NORM August 1995 Conical spring washers for screw and washer assemblies I 6908 ICs 21.060.30 Descriptors: Conical spring washers, screws, fasteners, washers. Spannscheiben fr Kombi-Schrauben Supersedes December 1990 edition. In keeping with current practice in standards published by the Int
2、ernational Organization for Standardization (ISO), a comma has been used throughout as the decimal marker. Foreword This standard has been prepared by the Normenausschuss Mechanische Verbindungselemente (Fasteners Standards Committee). A revision of the December 1990 edition was necessary to account
3、 for problems which have arisen when screw and washer assemblies include conical spring washers of nominal sizes 5,5 to 11, with low values for h. Therefore, these values have been significantly increased, the minimum values after testing for permanent set remaining nevertheless unchanged. As these
4、altered specifications do not conflict with the requirements specified in DIN 267-26, the interchangeability of products has not been affected. Amendments The following amendments have been made to the December 1990 edition. a) For sizes from 5,5 to 11, the minimum and maximum values of h, h,in and
5、h, have been amended. b) The standard has been editorially revised. Previous editions DIN 6908: 1972-12, 1990-12. Dimensions in mm 1 Scope and field of application This standard specifies dimensions and technical delivery conditions for conical spring washers which are intended for use with screw an
6、d washer assemblies as specified in DIN 6900-5. They are designed for use with bolted connections with bolts of property classes 8.8 to 10.9 (as specified in DIN EN 20 898-1). Conical spring washers are intended to coun- teract loosening of such connections (e.g. as a result of set- ting) (cf. DIN 2
7、67-26). They do not effectively prevent loos- ening of the connection under varying radial loads and are thus designed for use with short screws predominantly sub- ject to thrust. 2 Normative references This standard incorporates, by dated or undated reference, provisions from other publications. Th
8、ese normative ref- erences are cited at the appropriate places in the test, and the publications are listed hereafter. 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 re
9、ferences, the latest edition of the publication referred to applies. DIN 267-26 Fasteners; technical delivery conditions; steel spring washers for bolthut assemblies Steel flat products; cold rolled steel strip; dimensions, limit deviations and form tolerances Tabular layouts of article characterist
10、ics for washers Screw and washer assemblies; coarse threaded screws with captive conical spring washer Mechanical properties of fasteners; bolts, screws and DIN 1544 DIN 4000-3 DIN 6900-5 DIN EN 20898-1 studs (IS0 898-1 : 1988) Continued on pages 2 and 3. Beuth Verlag GmbH, Berlin, has the exclusive
11、 right of sale for German Standards (DIN-Normen). 01.96 DIN 6908 Engl. Price group 5 Sales No. O1 05 Page 2 DIN 6908 3 Dimensions Nominal size 2,253) 2,7!j3) 3,23) 3,6 4,55 595 774 Figure 1 Table 1 d2 S2) h As delivered Minimum size Mass For min.= max. max.= min. nominal nominal condition after test
12、 for (7,85 kg/dm3) thread size size for permanent per 1 O00 units, size dl max. min. set) in kg 2,251 2,35 6 5,70 0,5 0,72 0,61 0,61 0,l o M2,5 2,75 2,85 7 6,64 0,6 0,85 0,72 0,72 0,l 5 M3 3,20 3,32 8 7,64 0,8 1,06 0,92 0,92 0,27 M 33 3,60 3,72 9 8,64 1,0 1,30 1,12 1,12 0,42 M4 435 4,67 11 10,57 1,2
13、 1,55 1,35 1,35 0,74 M5 5,510 5,62 14 13,57 1,5 2,60 2,30 1,70 1,53 M6 7,40 755 18 17,57 2,O 3,lO 2,80 2,24 3,32 M8 Dimensions in mm 993 11 9,30 9,45 23 22,48 2,5 3,60 3,30 2,80 6,82 MIO 11,O 11,18 29 28,48 3,O 4,lO 3,80 3,43 13,3 M12 1) The specifications for the minimum free height of washers in t
14、able 5 of DIN 267-26, October 1987 edition, do not apply here. 2) The limit deviations for s shall be as specified in DIN 1544. 3) No spring force test values have as yet been specified for these nominal sizes. 4 Technical delivery conditions Conical spring washers shall be made of FSt steel as spec
15、ified in DIN 267-26 and comply with the technical delivery conditions specified there. 5 Designation Designation of a size 9,3 conical spring washer made of spring steel (FSt): Conical spring washer DIN 6908 - 9,3 - FSt The DIN 4000 - 3 - 3 tabular layout of article characteristics shall apply to co
16、nical spring washers as specified in this standard. I) Grade FSt steel shall also be used where no material is specified in existing documentation. DIN 6908 Page 3 Clearance hole diameter, dl H12 695 Appendix A Additional washer size (6,5) for replacement and maintenance purposes Thread size M7 is n
17、ot included in the international range of threads for screws and nuts, its further use is deprecated. However, should washers for use with M7 screw and washer assemblies be required as replacement parts (i.e. size 6,5), they may still be ordered with the dimensions specified in the table below. For d2 h S t Spring thread force, size in NI) Limit h14 k14 deviations M7 17 2,3 13 zk 0,08 0,3 3 930 Table Al Dimensions in mm Approximate mass (7,85 kgldm3) per 1 000 units, in kg 2,28 1) Calculated for washer when under load.
