1、CEN EN*IS0*772L- 2 74 3404589 O087265 308 W BRITISH STANDARD Specification for Countersunk flat head screws Part 2. Penetration depth of cross recesses The European Standard EN IS0 7721-2 : 1994 has the status of a British Standard UDC 621.882.215.6.091.6 BS EN IS0 7721-2 : 1995 CEN EN*IS0*772L- 2 7
2、4 H 3904589 0089266 244 m BS EN IS0 7721-2 : 1995 Standards Board and comes into Amd. No. Date effect on 15 January 1995 0 BSI 1995 Cooperating organizations Rxt affected The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the nati
3、onal standards organizations of the following countries: Austria Belgium Denmark Finland France Germany Greece Iceland Ireland Italy Luxembourg Netherlands Norway Portugal Spain Sweden Switzerland United Kingdom Oesterreichisches Normungsinstitut Institut belge de normalisation Dansk Standard Suomen
4、 Standardisoimisliito, r. y. Association francaise de normalisation Deutsches Institut fr Normung e.V. Hellenic Organization for Standardization Technological Institute of Iceland National Standards Authority of Ireland Ente Nazionale Italiano di Unificazione Inspection du Travail et des Mines Neder
5、lands Normalisatie-instituut Norges Standardiseringsforbund Instituto Portugus da Qualidade Asociacin Espaola de Normalizacin y Certificacin Standardiseringskommissionen i Sverige Association suisse de normalisation British Standards Institution The following BSI references relate to the work on thi
6、s standard: Committee reference GME/9 Draft for comment 89/70631 DC ISBN O 80 23629 3 CEN EN*IS0*7721- 2 94 3404589 0089267 180 BS EN IS0 7721-2 : 1995 Contents Page Cooperating organizations Inside front cover National foreword i Foreword 2 %xt of EN IS0 7721-2 3 National annex NA (informative) Com
7、mittees responsible Inside back cover National annex NB (informative) Cross-references Inside back cover National foreword This British Standard has been prepared under the direction of the Engineering Sector Board and is the English language version of EN IS0 7721-2 : 1994 CountersunkJZat head scre
8、ws - Part 2: Penetration th of cross recesses, published by the European Committee for Standardization (CEN). It is identical with IS0 7721-2 : 1990, published by the International Organization for Standardization (ISO). EN IS0 7721-2 : 1994 was produced as a result of international discussions in w
9、hich the United Kingdom took an active part. Compliance with a British Standard does not of itself confer immunity from legal obligations. i CEN EN*IS0*772L- 2 74 3404589 0087268 017 EUROPEAN STANDARD EN IS0 7721-2 NORME EUROPENNE EUROPISCHE NORM July 1994 UDC 621.882.215.6.091.6 Descriptors: fasten
10、ers, screws, countersunk head screws, cross recessed screws, dimensions English version Countersunk flat head screws - Part 2: Penetration depth of cross recesses (IS0 7721-2 : 1990) Vis mtaux tte fraise - Partie 2: Profondeur de pntration des empreintes Senkschrauben - Eil 2: Eindringtiefen von Kre
11、uzschlitzen cruciformes (IS0 7721-2 : 1990) (IS0 7721-2 : 1990) This European Standard was approved by CEN on 1994-07-26. CEN members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard withou
12、t 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 any other language mad
13、e 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, Iceland, Ireland, Italy,
14、 Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels O 1994 Copyright reserved to CEN members Ref. N
15、o. EN IS0 7721-2 : 1994 E CEN EN*ISO*72L- 2 94 a 3404589 00892b9 T53 9 Page 2 EN IS0 7721-2 : 1994 Foreword This European Standard has been taken over by the Technical Committee CEN/TC 185, Threaded and non-threaded mechanical fasteners and accessories, from the work of ISO/TC 2, Fasteners, of the I
16、nternational Organization for Standardization (EO) 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 January 1995, and conflicting national standards shall be withdrawn at the latest by January 1995
17、. According to the CENKENELEC Internal 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, United Kingdom. NOTE
18、. Normative references to international publications are listed in annex ZA (normative). CEN EN*IS0*772L- 2 94 m 3404589 0089270 775 Page 3 EN IS0 7721-2 : 1994 Countersunk flat head screws - Part 2: Penetration depth of cross recesses 1 Scope This part of IS0 7721 specifies the penetration depth of
19、 cross recesses of countersunk flat head screws for the two series 1 and 2 (deep and shallow, re- s p e c t ive ly). 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of IS0 7721. At the time of publication, th
20、e editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of IS0 7721 are encouraged to investi- gate the possibility of applying the most recent edi- tions of the standards indicated below. Members of IEC and IS0 maintain registers of curre
21、ntly valid International Standards. IS0 225:1983, Fasteners - Bolls, screws, studs and nuts - Symbols and designations of dimensions IS0 4757:1983, Cross recesses for screws IS0 7721:1983, Countersunk head screws - Head configuration and gauging. 3 Dimensions For application of the penetration depth
22、s of cross recesses specified in table 1, different underhead configurations are provided in order to attain suffi- cient head strength (see figure 1 and figure 2). Both types satisfy the conditions of the common head style as specified in IS0 7721” NOTE 1 specified in IS0 225. Symbols and designati
23、ons of dimensions are Figure 1 - Screw with underhead shoulder Jmax = 2 P Figure 2 - Screw without underhead shoulder 1) Will be revised and published under number IS0 7721-1 CEN EN*IS0*7723- 2 94 = 3404589 0089273 bo3 Page 4 EN IS0 7721-2 : 1994 Table 1 - Dimensions Dimensions In milllmetres :esses
24、 Series 2 Type H Penetration m depthti min max ref - 09 1,2 1,9 - 1,25 1,55 2,7 1,4 1,% 2,9 1,6 2,l 4,l Series ;hallow) Recess No. Thread Type Z Penetratlon depth2) min. I max. Type H Penetration depth21 min. max. ref. 0,6 0,9 1,6 0,9 1,2 1,9 0,9 1,2 1,9 1,4 i,% 2,9 1-7 2,l 3.2 1,9 2,4 4,4 2,l 2,6 4
25、,6 2,7 3,2 5,2 2,8 3,3 6,6 3,O 3,5 6,% 4,O 4,6 8,9 5,l 5,7 10 Type Z depth 2, min. m ref. Metric Other - ST2,2 M2.5 -. O I- O 0,95 1,20 1,9 0,95 1,20 2 1,4% 1,73 2,8 1,76 2,Ol 3 1,75 2,20 4,l 2,06 2.51 4,4 2,60 3,05 4,9 2,73 3,18 6,3 3.00 3.45 6,6 4,15 4,60 %,% 5,19 5,64 9,% ._ O 1 1 ST2,Q ST33 2 4
26、- 4,4 2 -r_ 3,9 4.4 %,7 43 5,3 2,06 2,27 2,72 2 3 3 6.3 895 - ST6.3 M10 4 4 9,4 I I I I Screws vvithout underhead shoulder Self-tapping screws Wood screws Screws of property class 4.8 Screws with underhead shoulder Screws of property classes 8.8 and 9.8 Thread cutting screws Thread forming screws Sc
27、rews without underhead shoulder entirely heat Screws of property Thread forming screws Thread cutting screws class 8.8 Application 31 1) Cross recesses in accordance with IS0 4757. 2) Penetration depth measured in accordance with IS0 4757. 3) Specified for steel screws, applicatlon for other materia
28、ls at manufacturers option. CEN EN*IS0*772L- 2 74 3404589 0087272 548 Page 5 EN IS0 7721-2 : 1994 Annex A (informative) Bibliography l IS0 7046:1983, Cross recessed countersunk flat head screws (common head style) - Product grade A and 2 IS0 7046-2:1990, Cross recessed countersunk flat head screws (
29、cornmon head style) - Grade A - Part 2: property class 4.8 only 21 Steel of property class 8.8, stainless sfeel and non-ferrous metals. - 2) Will be revised and published under number IS0 7046-1 Annex ZA (normative) Normative references to international publications with their relevant European publ
30、ications This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of
31、these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments). IEC Publication Year Title EN/HD Year IS0 225 1983 Fasteners - Bolts, screws, studs and E
32、N 20225 1991 nuts - Symbols and designation of dimensions IS0 4757 1983 Cross recesses for screws EN IS0 4757 1994 IS0 7721 1983 Countersunk head screws - Head EN 27721 1991 configuration and gauging CEN EN*IS0*772L- 2 94 3404587 008927Y 310 M BS EN IS0 7721-2 : 1995 National annex NA (informative)
33、Committees responsible The United Kingdom participation in the preparation of this European Standard was entrusted by the Engineering Sector Board to Echnical Committee GME/9, upon which the following bodies were represented : BEAMA Ltd. British Constructional Steelwork Association Ltd. British Indu
34、strial Fasteners Federation British Steel Industry British Steel Industry (Wire Section) Gauge and Tool Makers Association National Association of Fstener Stockholders Society of Motor Manufacturers and Traders Ltd. Washer Manufacturers Association of Great Britain The following bodies were also rep
35、resented in the drafting of the standard, through subcommittees and panels: British Plastics Federation Portable Electric Tool Manufacturers Association Small Electrical Appliances Marketing Association Timber Trade Federation National annex NB (informative) Cross-references Publication referred to
36、Corresponding British Standard IS0 225 : 1983 IS0 4757 : 1983 IS0 7721 : 1983 BS EN 20225 : 1992 Fasteners - Bolts, screws, studs and nuts - Symbols and designations of dimensions BS EN IS0 4757 : 1995 Cross recesses for screws BS EN 27721 : 1992 Countersunk head screws - Head configuration and gaug
37、m BS EN IS0 7721-2 : 1995 BSI 389 Chiswick High Road London W4 4AL 9501- 5- 0.5k- JWD 3404589 0089275 257 BSI - British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international leve
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