【国际标准】DIN 6912-2002 内六角中心低圆柱头螺钉.pdf

1、ICS 21.060.10 Zylinderschrauben mit Innensechskant Niedriger Kopf, mit Schlsselfhrung In keeping with current practice in standards published by the International Organization for Standardization (ISO), a comma has been used throughout as the decimal marker. Ref. No. DIN 6912 : 2002-12 English price

2、 group 07Sales No. 0107 09.03 DEUTSCHE NORMDecember 2002 6912 No part of this translation may be reproduced without the prior permission of DIN Deutsches Institut fr Normung e.V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany, has the exclusive right of sale for German Standards (DIN-Normen). Tra

3、nslation by DIN-Sprachendienst. In case of doubt, the German-language original should be consulted as the authoritative text. Hexagon socket thin head cap screws with pilot recess Continued on pages 2 to 8. Foreword This standard has been prepared by Technical Committee Schrauben mit Innenantrieb of

4、 the Normen- ausschuss Mechanische Verbindungselemente (Fasteners Standards Committee). The DIN 4000-2-1.2 tabular layout of article characteristics shall apply to screws covered in this standard. Amendments This standard differs from the May 1985 edition as follows: a) Hexagon socket head cap screw

5、s may now also be made of grade A4 stainless steel. b) For stainless steel screws, the range of sizes assigned to property class 70 has been changed. c) Minimum ultimate tensile loads have been specified. d) References have been updated. Previous editions DIN 6912: 1954x-03, 1967-12, 1985-05. All di

6、mensions are in millimetres. 1Scope This standard specifies dimensions and technical delivery conditions for sizes M4 to M36 hexagon socket head cap screws with pilot recess, of product grade A and made of steel, stainless steel or nonferrous metal. Where screws are to comply with specifications oth

7、er than those given in this standard, these shall be selected in accordance with the relevant standards (e.g. DIN EN 28839, DIN EN ISO 898-1, DIN EN ISO 3506-1, DIN EN ISO 4759-1, DIN ISO 261, and DIN ISO 965-2). Screws specified in this standard should not be used in the form of screw assemblies wi

8、th captive washers as they are always required to have a short unthreaded portion of shank to compensate for the pilot recess. Supersedes May 1985 edition. Page 2 DIN 6912 : 2002-12 2Normative references This standard incorporates, by dated or undated reference, provisions from other publications. T

9、hese norma- tive references are cited at 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

10、 undated references, the latest edition of the publication referred to applies. DIN 962Designation system for fasteners DIN 4000-2Tabular layouts of article characteristics for bolts, screws and fit bolts DIN EN 20225Bolts, screws, studs and nuts Symbols and designations for dimensioning (ISO 225 :

11、1983) DIN EN 26157-3Fasteners Surface discontinuities Part 3: Bolts, screws and studs for special require- ments (ISO 6157-3 : 1988) DIN EN 28839Mechanical properties of fasteners Bolts, screws, studs and nuts made of non-ferrous metals (ISO 8839 : 1986) DIN EN ISO 898-1Mechanical properties of fast

12、eners made of carbon steel and alloy steel Part 1: Bolts, screws and studs (ISO 898-1 : 1999) DIN EN ISO 3269Fasteners Acceptance inspection (ISO 3269 : 2000) DIN EN ISO 3506-1Mechanical properties of corrosion-resistant stainless steel fasteners Part 1: Bolts, screws and studs (ISO 3506-1 : 1997) D

13、IN EN ISO 4042Fasteners Electroplated coatings (ISO 4042 : 1999) DIN EN ISO 4753Fasteners Ends of parts with external ISO metric screw thread (ISO 4753 : 1999) DIN EN ISO 4759-1Tolerances for fasteners Part 1: Bolts, screws and nuts Product grades A, B and C (ISO 4759-1 : 2000) DIN EN ISO 10683Faste

14、ners Non-electrolytically applied zinc flake coatings (ISO 10683 : 2000) DIN ISO 261ISO general purpose metric screw threads General plan (ISO 261 : 1998) DIN ISO 965-2ISO general purpose metric screw threads Tolerances Part 2: Limits of sizes for gen- eral purpose external and internal screw thread

15、s Medium quality (ISO 965-2 : 1998) ISO 8992 : 1986Fasteners General requirements for bolts, screws, studs and nuts Page 3 DIN 6912 : 2002-12 3Dimensions Screw dimensions shall be as given in figure 1 and table 1. See DIN EN 20225 for symbols. Maximum underhead fillet lfmax = 1,7 rmax da,max ds,max

16、rmax = 2 For rmin, see table 1. Detail X Key to figure 1) End chamfered (cf. DIN EN ISO 4753). 2) Length of incomplete thread, u: 2 P maximum. 3) Slight rounding or countersinking at the mouth of the socket is permitted (no further than e). 4) Top edge of head rounded or chamfered (optional). 5) Bot

17、tom edge of head may be rounded or chamfered to dw, but shall always be free from burr. 6) Datum for dw. 7) ds applies if values of lsmin are specified. Figure 1: Screw dimensions (notation) 1) 2) 7) 3) 6) 5) 4) X Page 4 DIN 6912 : 2002-12 Table 1: Screw dimensions Thread size (d) Reference dimensio

18、n 2) 3) 4) Max. = nominal size Min. = nominal size Max. = nominal size Max. = nominal size Nominal size Nominal size 1) 5) 6) Shank length, ls, and grip length, lg Nominal size NOTE: Use of sizes in brackets should be avoided. 1) Thread pitch. 2) For lengths, l, of 125 mm or less. 3) For lengths, l,

19、 above 125 mm up to 200 mm. 4) For lengths, l, exceeding 200 mm. 5) emin = 1,14 smin. 6) Commercial sizes of screws are those for which lengths ls and lg have been specified. Nominal lengths, l, exceeding 200 mm shall be graded in 20 mm steps. For screws with lengths above the dashed line, the maxim

20、um distance between the last fully formed thread and the bearing face, lg, shall be equal to 5 P. For lengths below the line, lg and ls are to be calculated using the following equations:lgmax = lnom b; lsmin = lgmax 5 P. (continued) Page 5 DIN 6912 : 2002-12 Table 1 (concluded) Thread size (d) Refe

21、rence dimension 2) 3) 4) Max. = nominal size Min. = nominal size Max. = nominal size Max. = nominal size Nominal size Nominal size 1) 5) 6) Nominal size For footnotes, see page 4. Shank length, ls, and grip length, lg Page 6 DIN 6912 : 2002-12 MaterialSteelStainless steelNonferrous metal General req

22、uirementsAs specified in ISO 8992. Thread Tolerance6g As specified inDIN ISO 261 and DIN ISO 965-2. For sizes up to Property class1) 8.8 M24: A2-70 or CuZn2) (material)A4-70; for larger sizes: A2-50. As specified inDIN EN ISO 898-1.DIN EN ISO 3506-1.DIN EN 28839. Product gradeA As specified inDIN EN

23、 ISO 4759-1. As processed.PlainPlain DIN EN ISO 4042DIN EN ISO 4042 applies with regardapplies with regard to electroplating.to electroplating. DIN EN ISO 10683 applies with regard to zinc flake coatings. DIN EN 26157-3 applies with regard to limits for surface discontinuities. Acceptance As specifi

24、ed in DIN EN ISO 3269. inspection 1) See clause 5 for tensile strength requirements. 2) CU2 or CU3 grade copper-zinc alloy, at the manufacturers discretion. 4Technical delivery conditions Table 2: Technical delivery conditions Mechanical properties Limit deviations and geometrical tolerances Surface

25、 finish Surface discontinuities 5Reduced strength 5.1Screws made of steel (other than stainless) When tested as specified in DIN EN ISO 898-1 (test programme B), steel screws covered by this standard may not fulfill the tensile strength requirements for property class 8.8. All other requirements sha

26、ll be met. When testing full-size screws, the loads given in table 4 shall be applied. Any failure shall occur in the shank, along the free threaded length or at the head/shank transition. Page 7 DIN 6912 : 2002-12 Table 3: Minimum ultimate tensile loads for steel screws of property class 8.8 (equal

27、 to 80% of the loads required in DIN EN ISO 898-1) Thread size (d)M4M5M6M8M10M12M14 Minimum ultimate tensile 5 6209 08012 90023 40037 10053 90073 600 load, in N Thread size (d)M16M18M20M22M24M27M30 Minimum ultimate tensile 100 000127 000162 000202 000234 000309 000373 000 load, in N Thread size (d)M33M36 Minimum ultimate tensile 461 000542 000 load, in N 5.2Stainless steel screws In the case of stainless steel screws, the tensile strength shall be equal to 80% of the