1、February 2008 Translation by DIN-Sprachendienst.English price group 6No part of this translation may be reproduced without 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).IC
2、S 21.060.01!$lF“1733557www.din.deDDIN 974-1Diameters of counterbores Manufacturing dimensions Part 1: Hexagon socket head cap screws and screws with cheese heador pan headEnglish translation of DIN 974-1:2008-02Senkdurchmesser Konstruktionsmae Teil 1: Schrauben mit ZylinderkopfEnglische bersetzung v
3、on DIN 974-1:2008-02Diamtre de lamage Dimensions de fabrications Partie 1: Vis tte cylindriquesTraduction anglaise de DIN 974-1:2008-02SupersedesDIN 974-1:1991-05www.beuth.deDocument comprises pagesIn case of doubt, the German-language original shall be considered authoritative.911.10 DIN 974-1:2008
4、-02 Contents Page Foreword. 3 Introduction 4 1 Scope . 5 2 Normative references . 5 3 Counterbore diameters 5 4 Definition of a counterbore 7 5 General tolerances 8 Bibliography . 9 2 DIN 974-1:2008-02 Foreword This standard has been prepared by Working Committee NA 067-01-01 AA Referenznormen und Q
5、ualitts-management of the Normenausschuss Mechanische Verbindungselemente (Fasteners Standards Committee). Amendments This standard differs from DIN 974:1991-05 as follows: a) since DIN 7980 “Spring lock washers for use with pan head bolts” has been withdrawn without replace-ment, counterbore diamet
6、ers of series 3 (formerly given in Table 1) are no longer included; b) normative references have been revised and updated; c) the examples of suitable screws for the diameter series given in Table 1 have been updated; d) in Figure 1, details of surface roughness have been modified; e) the general to
7、lerances have been modified. Previous editions DIN 974: 1968-06, 1972-03 DIN 974-1: 1991-05 3 DIN 974-1:2008-02 Introduction Revision of this standard became necessary as most of the standards on washers referred to in the examples following Table 1 have been revised or withdrawn since the publicati
8、on of DIN 974-1:1991-05. 4 DIN 974-1:2008-02 1 Scope This standard specifies diameters of counterbores for hexagon socket head cap screws and screws with cheese head or pan head, used with or without washer in components with clearance holes. 2 Normative references The following referenced documents
9、 are indispensable for the application of this document. For dated refer-ences, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. DIN EN 20273, Fasteners Clearance holes for bolts and screws DIN ISO 2768-1, Gener
10、al tolerances Tolerances for linear and angular dimensions without individual tolerance indications DIN ISO 2768-2, General tolerances Geometrical tolerances for features without individual tolerance indi-cations 3 Counterbore diameters This standard specifies five series of counterbore diameters, d
11、1, as a function of screw type, of whether used with or without washer and, if used with washer, of the washer type. The associated medium series clearance hole diameters as specified in DIN EN 20273 have been given for information in Table 1. 5 DIN 974-1:2008-02 Table 1 Counterbore diameters d1Dime
12、nsions in millimetres Screws used without washers Screw and washer assembliesaCounterbore diameter d1bH 13 Nominal thread diameter d Diameter of DIN EN 20273 clearance hole, medium series d2Series 1 Series 2 Series 4 Series 5 Series 6 1 1,2 1,4 1,2 1,4 1,6 2,2 2,5 3 1,6 1,8 2 1,8 2,1 2,4 3,5 3,8 4,4
13、 3,5 5 5,5 6 6 2,5 3 3,5 2,9 3,4 3,9 5,5 6,5 6,5 6 7 8 6 7 8 7 9 9 7 8 9 4 5 6 4,5 5,5 6,6 8 10 11 9 11 13 9 11 13 10 13 15 10 13 15 8 10 12 9 11 13,5 15 18 20 18 24 16 20 24 18 24 26 20 24 33 14 16 18 15,5 17,5 20 24 26 30 26 30 33 30 33 36 40 43 46 20 22 24 22 24 26 33 36 40 36 40 43 40 43 48 48 5
14、4 58 27 30 33 30 33 36 46 50 54 46 54 54 61 63 63 73 36 42 48 39 45 52 58 69 78 63 73 82 69 82 98 56 64 72 62 70 78 93 107 118 93 107 118 112 125 132 80 90 100 86 96 107 132 145 160 132 145 160 150 170 182 aWhere more than one washer is used, selection of the series shall be based on the washer with
15、 the largest diameter. bThe diameters only apply for those screws or washers which are actually included in the relevant dimensional standard. Where there is the risk of the edge of the hole being damaged by the screw underhead fillet, the edge (d2) shall be chamfered. This, however, will increase t
16、he pressure on the head bearing face. 6 DIN 974-1:2008-02 Examples of suitable screws for the diameter series given in Table 1: Series 1: for DIN 6912, DIN 7984, DIN 34821, DIN EN ISO 1207, DIN EN ISO 4762, DIN EN ISO 14579 and DIN EN ISO 14580 screws, used without washer. NOTE 1 The diameters speci
17、fied also apply for thread cutting screws as in DIN 7513 and DIN 7516 and for thread rolling screws as in DIN 7500-1, if their head complies with the specifications of the relevant dimensional standard. Series 2: for DIN EN ISO 1580, DIN EN ISO 7045 and DIN EN ISO 14583 screws, used without washer.
18、NOTE 2 The diameters specified also apply for thread cutting screws as in DIN 7513 and DIN 7516 and for thread rolling screws as in DIN 7500-1, if their head complies with the specifications of the relevant dimensional standard. Series 4: for hexagon socket head cap screws and screws with cheese hea
19、d or pan head, used with DIN EN ISO 7092 or DIN EN ISO 10673 (type S) washer. Series 5: for hexagon socket head cap screws and screws with cheese head or pan head, used with DIN EN ISO 7089, DIN EN ISO 7090 or DIN EN ISO 10673 (type S) washer. Series 6: for hexagon socket head cap screws and screws
20、with cheese head or pan head, used with DIN 6796 or DIN 6908 washer. 4 Definition of a counterbore A counterbore is defined by its diameter, d1, and its depths, t (see Figure 1). Key d1counterbore diameter d2diameter of clearance hole t counterbore depth Figure 1 Counterbore dimensions (notation) Th
21、is standard does not specify the depth, which is to be chosen as a function of the particular application. It is, however, recommended that the required depth be determined as follows. For the screw head to be flush with the component surface, the required depth, t, is obtained as the sum of the max
22、imum values of head height and washer height plus an allowance as specified in Table 2. 7 DIN 974-1:2008-02 Table 2 Allowance for determining counterbore depth, t Dimensions in millimetres Nominal thread diameter d Allowance 1 d 1,4 d 6 d 20 d 27 d 1,4 6 20 27 100 0,2 0,4 0,6 0,8 1,0 EXAMPLE Determi
23、nation of counterbore depth, t, for an ISO 4762 M12 60 10.9 hexagon socket head cap screw used with an ISO 7092 12 300 HV washer: maximum head height: kmax= 12 mm maximum washer thickness: hmax= 2,2 mm allowance: 0,6 mm t = kmax+ hmax+ allowance = 14,8 mm The result is to be rounded as required. Whe
24、re more than one washer is used (e.g. for screw and washer assemblies), the maximum washer heights shall be added to obtain hmax. 5 General tolerances Sizes (except d1), form and position are subject to the general tolerances as in DIN ISO 2768-1 and DIN ISO 2768-2 indicated on the drawing. Where no
25、 such tolerances are specified, the general tolerances shall be class mK tolerances as in ISO 2768-2. 8 DIN 974-1:2008-02 9 Bibliography DIN 6796, Conical spring washers for bolted connections DIN 6908, Conical spring washers for screw and washer assemblies DIN 6912, Hexagon socket thin head cap scr
26、ews with pilot recess DIN 7500-1, Thread rolling screws for ISO metric thread Part 1: Technical delivery conditions for case hard-ened and tempered screws DIN 7513, Hexagon head and slotted head thread cutting screws - Dimensions, requirements and testing DIN 7516, Cross recessed head thread cutting
27、 screws Dimensions, requirements and testing DIN 7984, Hexagon socket head cap screws with low head DIN 34821, Cheese head screws with 12 point socket DIN EN ISO 1207, Slotted cheese head screws Product grade A DIN EN ISO 1580, Slotted pan head screws Product grade A DIN EN ISO 4762, Hexagon socket
28、head cap screws DIN EN ISO 7045, Pan head screws with type H or type Z cross recess Product grade A DIN EN ISO 7089, Plain washers Normal series Product grade DIN EN ISO 7090, Plain washers, chamfered Normal series Product grade A DIN EN ISO 7092, Plain washers Small series Product grade A DIN EN ISO 10673, Plain washers for screw and washer assemblies Small, normal and large series Product grade A DIN EN ISO 14579, Hexalobular socket head cap screws DIN EN ISO 14580, Hexalobular socket cheese head screws DIN EN ISO 14583, Hexalobular socket pan head screws
