1、BRITISH STANDARD BS EN ISO 4757:1995 Cross recesses for screws The European Standard ENISO4757:1994 has the status of a British Standard UDC 621.882.215.6BSENISO4757:1995 This British Standard, having been prepared under the directionof the Engineering SectorBoard, was published underthe authority o
2、f the Standards Board and comes into effect on 15 January 1995 BSI 08-1999 The following BSI references relate to the work on this standard: Committee reference GME/9 Draft for comment 82/70263 DC ISBN 0 580 23626 9 Cooperating organizations The European Committee for Standardization (CEN), under wh
3、ose supervision this European Standard was prepared, comprises the national standards organizations of the following countries: Austria Oesterreichisches Normungsinstitut Belgium Institut belge de normalisation Denmark Dansk Standard Finland Suomen Standardisoimisliito, r.y. France Association frana
4、ise de normalisation Germany Deutsches Institut fr Normung e.V. Greece Hellenic Organization for Standardization Iceland Technological Institute of Iceland Ireland National Standards Authority of Ireland Italy Ente Nazionale Italiano di Unificazione Luxembourg Inspection du Travail et des Mines Neth
5、erlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Instituto Portugus da Qualidade Spain Asociacin Espaola de Normalizacin y Certificacin Sweden Standardiseringskommissionen i Sverige Switzerland Association suisse de normalisation United Kingdom British Standar
6、ds Institution Amendments issued since publication Amd. No. Date CommentsBSENISO4757:1995 BSI 08-1999 i Contents Page Cooperating organizations Inside front cover National foreword ii Foreword 2 1 Scope and field of application 3 2 Recess type H 3 3 Recess type Z 6 National annex NA (informative) Co
7、mmittees responsible Inside back cover Table 1 Recess type H 3 Table 2 Gauge dimensions for recess type H 5 Table 3 Recess type Z 7 Table 4 Gauge dimensions for recess type Z 9BSENISO4757:1995 ii BSI 08-1999 National foreword This British Standard has been prepared under the direction of the Enginee
8、ring Sector Board and is the English language version of ENISO4757:1994 Cross recesses for screws, published by the European Committee for Standardization (CEN). It is identical with ISO4757:1983, published by the International Organization for Standardization (ISO). ENISO4757:1994 was produced as a
9、 result of international discussions in which the UnitedKingdom took an active part. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of its
10、elf confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theEN ISO title page, pages2 to10, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorpora
11、ted. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM ENISO 4757 July1994 UDC 621.882.215.6 Descriptors: Fasteners, screws, cruciform recessed screws, dimensions English version Cross recesses for screws (ISO 4757:1983) Emprein
12、tes cruciformes pour vis (ISO4757:1983) Kreuzschlitze fr Schrauben (ISO 4757:1983) This European Standard was approved by CEN on 1994-07-26. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a nati
13、onal standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in an
14、y other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Icel
15、and, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1994 Copyright reserved to C
16、EN members Ref. No. EN ISO 4757:1994 EENISO4757:1994 BSI 08-1999 2 Foreword This European Standard has been taken over by the Technical Committee CEN/TC185, Threaded and non-threaded mechanical fasteners and accessories, from the work of ISO/TC2, Fasteners, of the International Organization for Stan
17、dardization (ISO). This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by January1995, and conflicting national standards shall be withdrawn at the latest by January1995. According to the CEN/CENELEC Int
18、ernal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, UnitedKingdom.ENISO4757:1994 BSI 08-1999 3 1 Scope an
19、d field of application This International Standard defines two types of cross recesses for screws: recess type H; recess type Z. Included in this International Standard is a method of penetration gauging for both types. 2 Recess type H 2.1 Dimensions Table 1 Recess type H Dimensions in millimetres R
20、ecess No. 0 1 2 3 4 b 0,61 0,97 1,47 2,41 3,48 e 0,26 0,36 0,41 0,46 0,79 0,84 1,98 2,03 2,39 2,44 g 0,81 1,27 2,29 3,81 5,08 f 0,31 0,36 0,51 0,56 0,66 0,74 0,79 0,86 1,19 1,27 r nom. 0,3 0,5 0,6 0,8 1 t 1 ref. 0,22 0,34 0,61 1,01 1,35 a 138 140 146 153 7 7 5 45 5 45 7 a This will be replaced by r
21、min.0,25mm; r max. 0,36mm. Dimensions shown are theoretical values. 0 0,03 +0,05 0 0 15 9 +159 0 ENISO4757:1994 4 BSI 08-1999 2.2 Recess penetration gauging and gauge dimensions for recess type H The penetration depth of the depth gauge (minimum dimension) is indicated in the different product stand
22、ards. It is the test dimension for the usability of the cross recess. The point of the gauge is identical with the point of the respective screwdriver. A sleeve serves to guide the gauge and fix the reference plane. This plane passes through the point of intersection of the recess wings and the top
23、surface of the screw head. It corresponds thus to the surface of a screw with flat head. In the case of crowned screw heads, it lies below the crown in the transition area from the recess wings to the surface of the head. For these screw heads, the reference plane is fixed with the help of the beari
24、ng surfaces of the gauge sleeve. The penetration depth of the gauge is measured from the reference plane by using a dial gauge. The zero and control positions of the depth gauge can be found on a flat surface. Due to the permissible error for the core thickness b of the gauge point, an inaccuracy of
25、 up to0,13mm can arise when measuring the penetration depth.ENISO4757:1994 BSI 08-1999 5 Table 2 Gauge dimensions for recess type H Dimensions in millimetres Gauge No. 0 1 2 3 4 b 0,64 1,001 1,539 2,497 3,574 g 0,813 1,27 2,286 3,81 5,08 d 0,25 0,38 0,38 0,38 0,38 e 0,315 0,513 1,102 2,098 2,738 f 0
26、,31 0,51 0,64 0,79 1,12 l min. 3,17 3,17 4,78 7,14 8,74 a 138 140 146 153 7 7 5 45 5 45 7 a This will be replaced by r = 0,25 0,025 mm. 0 0,025 +0,025 0 +0,13 0 0 0,025 0 0,06 +159 0 0 159ENISO4757:1994 6 BSI 08-1999 3 Recess type Z 3.1 DimensionsENISO4757:1994 BSI 08-1999 7 Table 3 Recess type Z 3.
27、2 Recess penetration gauging and gauge dimensions for recess type Z The penetration depth of the depth gauge (minimum and maximum dimension) is indicated in the different product standards. It is the test dimension for the usability of the cross recess. The point of the gauge is identical with the p
28、oint of the respective screwdriver. A sleeve serves to guide the gauge and fix the reference plane. This plane passes through the point of intersection of the recess wings and the top surface of the screw head. It corresponds thus to the surface of a screw with flat head. In the case of crowned scre
29、w heads, it lies below the crown in the transition area from the recess wings to the surface of the head. For these screw heads, the reference plane is fixed with the help of the bearing surfaces of the gauge sleeve. The penetration depth of the gauge is measured from the reference plane by using a
30、dial gauge. The zero and control positions of the depth gauge can be found on a flat surface. Dimensions in millimetres Recess No. 0 1 2 3 4 b 0,76 1,27 1,83 2,72 3,96 f 0,48 0,74 1,03 1,42 2,16 g 0,86 1,32 2,34 3,86 5,08 r 1 max. 0,30 0,30 0,38 0,51 0,64 r 2 max. 0,10 0,13 0,15 0,25 0,38 j max. 0,1
31、3 0,15 0,15 0,20 0,20 7 7 5 45 5 45 7 7 45 7 45 6 20 6 20 7 45 4 23 4 23 3 3 4 23 46 46 46 56 15 56 15 Dimensions shown are theoretical values. 0 0,05 0 0,025 0 0,05 +159 0 0 159 0 159 0 7 9ENISO4757:1994 8 BSI 08-1999ENISO4757:1994 BSI 08-1999 9 Table 4 Gauge dimensions for recess type Z Dimensions
32、 in millimetres Gauge No. 0 1 2 3 4 b max. 0,711 1,112 1,702 2,591 3,861 min. 0,673 1,074 1,664 2,553 3,823 f max. 0,445 0,698 0,990 1,372 2,083 min. 0,420 0,673 0,965 1,346 2,057 g max. 0,915 1,397 2,438 3,962 5,182 min. 0,800 1,372 2,413 3,937 5,157 l min. 3,17 3,17 4,78 7,14 8,74 p max. 0,077 0,1
33、66 0,331 0,585 0,788 min. 0,064 0,153 0,318 0,572 0,775 r max. 0,1 0,13 0,2 0,31 0,51 min. 0,08 0,1 0,15 0,2 0,36 7 7 5 45 5 45 7 7 45 7 45 6 20 6 20 7 45 4 23 4 23 3 3 4 23 46 46 46 56 15 56 15 0 69 +69 0 +69 0 +79 010 blankBSENISO4757:1995 BSI 08-1999 National annex NA (informative) Committees res
34、ponsible The United Kingdom participation in the preparation of this European Standard was entrusted by the Engineering Sector Board to Technical Committee GME/9, upon which the following bodies were represented: BEAMA Ltd. British Constructional Steelwork Association Ltd. British Industrial Fastene
35、rs Federation British Steel Industry British Steel Industry (Wire Section) Gauge and Tool Makers Association National Association of Fastener Stockholders Society of Motor Manufacturers and Traders Ltd. Washer Manufacturers Association of Great Britain The following bodies were also represented in t
36、he drafting of the standard, through subcommittees and panels: British Plastics Federation Portable Electric Tool Manufacturers Association Small Electrical Appliances Marketing Association Timber Trade FederationBS EN ISO 4757:1995 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitu
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