1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 7050:2011Cross-recessed countersunk(flat) head tapping screws (ISO7050:2011)BS EN ISO 7050:2011 BRITISH STANDARDNational forewordThis British Standard is the UK impleme
2、ntation of EN ISO 7050:2011.It supersedes BS EN ISO 7050:1995 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee FME/9/3, Fasteners - Product Standards.A list of organizations represented on this committee can beobtained on request to its secretary.This pu
3、blication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 68778 5ICS 21.060.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the
4、authority of theStandards Policy and Strategy Committee on 31 August 2011.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 7050 August 2011 ICS 21.060.10 Supersedes EN ISO 7050:1994English Version Cross-recessed countersunk (flat) head tap
5、ping screws (ISO 7050:2011) Vis tle tte fraise empreinte cruciforme (ISO 7050:2011) Senk-Blechschrauben mit Kreuzschlitz (ISO 7050:2011) This European Standard was approved by CEN on 1 July 2011. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions
6、 for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in t
7、hree official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards
8、bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United
9、 Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 7050:2011:
10、 EBS EN ISO 7050:2011EN ISO 7050:2011 (E) 3 Foreword This document (EN ISO 7050:2011) has been prepared by Technical Committee ISO/TC 2 “Fasteners“ in collaboration with Technical Committee CEN/TC 185 “Fasteners” the secretariat of which is held by DIN. This European Standard shall be given the stat
11、us of a national standard, either by publication of an identical text or by endorsement, at the latest by February 2012, and conflicting national standards shall be withdrawn at the latest by February 2012. Attention is drawn to the possibility that some of the elements of this document may be the s
12、ubject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN ISO 7050:1994. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implemen
13、t this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switze
14、rland and the United Kingdom. Endorsement notice The text of ISO 7050:2011 has been approved by CEN as a EN ISO 7050:2011 without any modification. BS EN ISO 7050:2011ISO 7050:2011(E) ISO 2011 All rights reserved iiiForeword ISO (the International Organization for Standardization) is a worldwide fed
15、eration of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that comm
16、ittee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accorda
17、nce with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires
18、 approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 7050 was prepared by Technical Co
19、mmittee ISO/TC 2, Fasteners, Subcommittee SC 13, Fasteners with non-metric thread. This second edition cancels and replaces the first edition (ISO 7050:1983), which has been technically revised. BS EN ISO 7050:2011BS EN ISO 7050:2011INTERNATIONAL STANDARD ISO 7050:2011(E) ISO 2011 All rights reserve
20、d 1Cross-recessed countersunk (flat) head tapping screws 1 Scope This International Standard specifies the characteristics of cross-recessed pan head tapping screws with thread sizes from ST 2,2 to ST 9,5 inclusive. 2 Normative references The following referenced documents are indispensable for the
21、application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 225, Fasteners Bolts, screws, studs and nuts Symbols and descriptions of dimensions ISO 1478, Tapping scre
22、ws thread ISO 2702, Heat-treated steel tapping screws Mechanical properties ISO 3269, Fasteners Acceptance inspection ISO 3506-4, Mechanical properties of corrosion-resistant stainless steel fasteners Part 4: Tapping screws ISO 4042, Fasteners Electroplated coatings ISO 4757, Cross recesses for scre
23、ws ISO 4759-1, Tolerances for fasteners Part 1: Bolts, screws, studs and nuts Product grades A, B and C ISO 7721, Countersunk head screws Head configuration and gauging ISO 7721-2, Countersunk flat head screws Part 2: Penetration depth of cross recesses ISO 8992, Fasteners General requirements for b
24、olts, screws, studs and nuts ISO 10683, Fasteners Non-electrolytically applied zinc flake coatings ISO 16048, Passivation of corrosion-resistant stainless-steel fasteners BS EN ISO 7050:2011ISO 7050:2011(E) 2 ISO 2011 All rights reserved3 Dimensions See Figure 1 and Table 1. Symbols and descriptions
25、 of dimensions are specified in ISO 225. a) Type C b) Type F c) Type R d) Type H Cross recess e) Type Z Cross recess aEdge rounded or flat. bDimension a shall be measured at the core diameter of the first full thread. Figure 1 Cross-recessed countersunk (flat) head tapping screw BS EN ISO 7050:2011I
26、SO 7050:2011(E) ISO 2011 All rights reserved 3Table 1 Dimensions Dimensions in millimetres Thread size ST 2,2 ST 2,9 ST 3,5 ST 4,2 ST 4,8 ST 5,5 ST 6,3 ST 8 ST 9,5Pa0,8 1,1 1,3 1,4 1,6 1,8 1,8 2,1 2,1 a max. 1,6 2,2 2,6 2,8 3,2 3,6 3,6 4,2 4,2 Theoreticalbmax. 4,4 6,3 8,2 9,4 10,4 11,5 12,6 17,3 20,
27、0 max. 3,8 5,5 7,3 8,4 9,3 10,3 11,3 15,8 18,3 dkActual min. 3,5 5,2 6,9 8,0 8,9 9,9 10,9 15,4 17,8 k max. 1,10 1,70 2,35 2,60 2,80 3,00 3,15 4,65 5,25 r max. 0,8 1,2 1,4 1,6 2,0 2,2 2,4 3,2 4,0 Recess No 0 1 2 3 4 m ref. 1,9 3,2 4,4 4,6 5,2 6,6 6,8 8,9 10,0 max 1,2 2,1 2,4 2,6 3,2 3,3 3,5 4,6 5,7 T
28、ype H Penetration min. 0,9 1,7 1,9 2,1 2,7 2,8 3,0 4,0 5,1 m ref. 2,0 3,0 4,1 4,4 4,9 6,3 6,6 8,8 9,8 max. 1,20 2,01 2,20 2,51 3,05 3,18 3,45 4,60 5,64 Cross recess Series 1 (deep) Type Z Penetration min. 0,95 1,76 1,75 2,06 2,60 2,73 3,00 4,15 5,19 Type C 2,0 2,6 3,2 3,7 4,3 5,0 6,0 7,5 8,0 Type F
29、1,6 2,1 2,5 2,8 3,2 3,6 3,6 4,2 4,2 y ref. Type R 2,7 3,2 3,6 4,3 5,0 6,3 lcType C and Type R Type F nom. min. max. min. max. 4,5 3,7 5,3 3,7 4,5 6,5 5,7 7,3 5,7 6,5 9,5 8,7 10,3 8,7 9,5 13 12,2 13,8 12,2 13,0 Range 16 15,2 16,8 15,2 16,0 of 19 18,2 19,8 18,2 19,0 preferred 22 21,2 22,8 20,7 22,0 le
30、ngths 25 24,2 25,8 23,7 25,0 32 30,7 33,3 30,7 32,0 38 36,7 39,3 36,7 38,0 45 43,7 46,3 43,5 45,0 50 48,7 51,3 48,5 50,0 aP = pitch of the thread. bIn accordance with ISO 7721. cSizes with lengths marked with a dash () cannot be manufactured. BS EN ISO 7050:2011ISO 7050:2011(E) 4 ISO 2011 All rights
31、 reserved4 Specifications and reference International Standards See Table 2. Table 2 Specifications and reference International Standards Material Steel, in accordance with ISO 2702 Stainless steel General requirements ISO 8992 Thread ISO 1478 Cross recess ISO 4757, ISO 7721-2 Steel grade/ hardness
32、class A2-20H, A4-20H, A5-20H Mechanical propertyInternational Standard ISO 2702 ISO 3506-4 Product grade A Tolerances International Standard ISO 4759-1 As processed Finish Coating Requirements for electroplating are specified in ISO 4042. Requirements for non-electrolytically applied zinc flake coat
33、ings are specified in ISO 10683. Additional requirements or other finishes or coatings shall be agreed between the supplier and the purchaser. Requirements for passivation are specified in ISO 16048. Acceptability Acceptance inspection is specified in ISO 3269. 5 Designation EXAMPLE 1 A cross-recess
34、ed countersunk (flat) head tapping screw with thread size ST 3,5, nominal length l = 16 mm, made of steel (St) in accordance with ISO 2702, rounded end (Type R) and cross recess Type Z is designated as follows: Tapping screw ISO 7050 - ST 3,5 16 - St - R - Z EXAMPLE 2 A cross-recessed countersunk (f
35、lat) head tapping screw with thread size ST 3,5, nominal length l = 16 mm, made of stainless steel (A4-20H) in accordance with ISO 3506-4, rounded end (Type R) and cross recess Type H is designated as follows: Tapping screw ISO 7050 - ST 3,5 16 - A4-20H - R - H BS EN ISO 7050:2011This page deliberat
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