1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 7046-2:2011Countersunk flat head screws(common head style) withtype H or type Z cross recess Product grade APart 2: Steel screws of property class 8.8,stainless steel s
2、crews and non-ferrous metalscrews (ISO 7046-2:2011)BS EN ISO 7046-2:2011 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO 7046-2:2011. It supersedes BS EN ISO 7046-2:1995 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCom
3、mittee FME/9/3, Fasteners - Product Standards.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011 ISBN 978 0
4、 580 72977 5 ICS 21.060.10 Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 September 2011. Amendments issued since publicationDate T e x t a f f e c t e dEUROPE
5、AN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 7046-2 September 2011 ICS 21.060.10 Supersedes EN ISO 7046-2:1994English Version Countersunk flat head screws (common head style) with type H or type Z cross recess - Product grade A - Part 2: Steel screws of property class 8.8, stainless steel scre
6、ws and non-ferrous metal screws (ISO 7046-2:2011) Vis mtaux tte fraise empreinte cruciforme de type H ou de type Z - Grade A - Partie 2: Vis en acier de classe de qualit 8.8, vis en acier inoxydable et vis en mtaux non ferreux (ISO 7046-2:2011) Senkschrauben (Einheitskopf) mit Kreuzschlitz Form H od
7、er Form Z - Produktklasse A - Teil 2: Stahl mit Festigkeitsklasse 8.8, nichtrostender Stahl und Nichteisenmetalle (ISO 7046-2:2011) This European Standard was approved by CEN on 8 August 2011. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions fo
8、r 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 thre
9、e 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 bod
10、ies 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 Ki
11、ngdom. 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 7046-2:2011:
12、EBS EN ISO 7046-2:2011EN ISO 7046-2:2011 (E) 3 Foreword This document (EN ISO 7046-2:2011) 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
13、 status of a national standard, either by publication of an identical text or by endorsement, at the latest by March 2012, and conflicting national standards shall be withdrawn at the latest by March 2012. Attention is drawn to the possibility that some of the elements of this document may be the su
14、bject 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 7046-2:1994. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to impleme
15、nt 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, Switz
16、erland and the United Kingdom. Endorsement notice The text of ISO 7046-2:2011 has been approved by CEN as a EN ISO 7046-2:2011 without any modification. BS EN ISO 7046-2:2011ISO 7046-2:2011(E) ISO 2011 All rights reserved iiiForeword ISO (the International Organization for Standardization) is a worl
17、dwide federation 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
18、that committee. 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 i
19、n accordance 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
20、 requires 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 7046-2 was prepared by T
21、echnical Committee ISO/TC 2, Fasteners, Subcommittee SC 11, Fasteners with metric external thread. This second edition cancels and replaces the first edition (ISO 7046-2:1990), of which it constitutes a minor revision. ISO 7046 consists of the following parts, under the general title Countersunk fla
22、t head screws (common head style) with type H or type Z cross recess Product grade A: Part 1: Steel screws of property class 4.8 Part 2: Steel screws of property class 8.8, stainless steel screws and non-ferrous metal screws BS EN ISO 7046-2:2011ISO 7046-2:2011(E) iv ISO 2011 All rights reservedIntr
23、oduction The penetration depth of cross recesses for countersunk flat head screws is intended to satisfy two requirements, which act in opposite directions for a given head dimension. Firstly, there is the requirement for sufficient head strength to attain the proof and breaking Ioads of the respect
24、ive property class. A shallow cross recess increases the head strength. On the other hand, it is necessary for the wrench ability of the screw to be satisfactory; this can only be achieved by a sufficiently deep cross recess. ISO 7721-2 was developed in order to find a compromise which, as far as po
25、ssible, would meet both requirements. ISO 7721-2 specifies deep cross recesses for countersunk head screws of low strength: a good wrench ability is achieved and the head strength is still sufficient. This execution is used in ISO 7046-1 (see the Foreword). For screws of higher strength, sufficient
26、head strength can only be attained by a shallower penetration depth of the cross recesses. If such screws also require good wrench ability, then, under the conditions of the common head style, it is necessary for a shoulder to be provided under the head, in addition to the larger penetration depth,
27、in order to guarantee sufficient head strength. This part of ISO 7046 covers both possibilities. This compromise, which unfortunately results in different, but interchangeable, types of cross-recessed flat countersunk head screws, is the only way of reaching an agreement at the international level.
28、BS EN ISO 7046-2:2011INTERNATIONAL STANDARD ISO 7046-2:2011(E) ISO 2011 All rights reserved 1Countersunk flat head screws (common head style) with type H or type Z cross recess Product grade A Part 2: Steel screws of property class 8.8, stainless steel screws and non-ferrous metal screws 1 Scope Thi
29、s part of ISO 7046 specifies the characteristics of recessed countersunk flat head screws with threads M2 up to and including M10, of grade A and of property class 8.8 for steel, A2-70 for stainless steel and CU2 and CU3 for non-ferrous metals. If, in special cases, specifications other than those l
30、isted in this part of ISO 7046 are required, they can be selected from existing International Standards, for example ISO 261, ISO 888, ISO 898-1, ISO 965-2, ISO 3506-1, ISO 4759-1 and ISO 8839. 2 Normative references The following referenced documents are indispensable for the application of this do
31、cument. 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 261, ISO general purpose metric screw th
32、reads General plan ISO 898-1, Mechanical properties of fasteners made of carbon steel and alloy steel Part 1: Bolts, screws and studs with specified property classes Coarse thread and fine pitch thread ISO 965-2, ISO general purpose metric screw threads Tolerances Part 2: Limits of sizes for general
33、 purpose external and internal screw threads Medium quality ISO 3269, Fasteners Acceptance inspection ISO 3506-1, Mechanical properties of corrosion-resistant stainless steel fasteners Part 1: Bolts, screws and studs ISO 4042, Fasteners Electroplated coatings ISO 4757, Cross recesses for screws ISO
34、4759-1, Tolerances for fasteners Part 1: Bolts, screws, studs and nuts Product grades A, B and C ISO 6157-1, Fasteners Surface discontinuities Part 1: Bolts, screws and studs for general requirements ISO 6157-3, Fasteners Surface discontinuities Part 3: Bolts, screws and studs for special requiremen
35、ts BS EN ISO 7046-2:2011ISO 7046-2:2011(E) 2 ISO 2011 All rights reservedISO 7721-2, Countersunk flat head screws Part 2: Penetration depth of cross recesses ISO 8839, Mechanical properties of fasteners Bolts, screws, studs and nuts made of non-ferrous metals ISO 10683, Fasteners Non-electrolyticall
36、y applied zinc flake coatings ISO 16048, Passivation of corrosion-resistant stainless-steel fasteners 3 Dimensions See Figures 1, 2 and 3 and Table 1. Symbols and descriptions of dimensions are specified in ISO 225. The shank diameter is approximately equal to the pitch diameter or equal to the perm
37、issible major thread diameter. amax= 2,5P NOTE For other dimensions, see Figures 2 and 3. Figure 1 Screw with underhead shoulder for penetration depth series 1 Deep amax= 2P Key 1 as-rolled end 2 edge (rounded or flat) Figure 2 Screw without underhead shoulder for penetration depth series 2 Shallow
38、BS EN ISO 7046-2:2011ISO 7046-2:2011(E) ISO 2011 All rights reserved 3a) Type H b) Type Z Figure 3 Cross recess Table 1 Dimensions Dimensions in millimetres Thread, d M2 M2,5 M3 (M3,5)aM4 M5 M6 M8 M10 Pb0,4 0,45 0,5 0,6 0,7 0,8 1 1,25 1,5 b min. 25 25 25 38 38 38 38 38 38 Theoretical max. 4,4 5,5 6,
39、3 8,2 9,4 10,4 12,6 17,3 20 max. 3,8 4,7 5,5 7,3 8,4 9,3 11,3 15,8 18,3 dkcActual min. 3,5 4,4 5,2 6,9 8,0 8,9 10,9 15,4 17,8 k max. 1,2 1,5 1,65 2,35 2,7 2,7 3,3 4,65 5 r max. 0,5 0,6 0,8 0,9 1 1,3 1,5 2 2,5 x max. 1 1,1 1,25 1,5 1,75 2 2,5 3,2 3,8 Recess no. 0 1 2 3 4 m ref. 1,9 2,9 3,2 4,4 4,6 5,
40、2 6,8 8,9 10 min. 0,9 1,4 1,7 1,9 2,1 2,7 3,0 4,0 5,1 Type H Penetration depth max. 1,2 1,8 2,1 2,4 2,6 3,2 3,5 4,6 5,7 Recess no. 0 1 2 3 4 m ref. 1,9 2,8 3 4,1 4,4 4,9 6,6 8,8 9,8 min. 0,95 1,48 1,76 1,75 2,06 2,60 3,00 4,15 5,19 Series 1d (deep) Type Z Penetration depth max. 1,20 1,73 2,01 2,20 2
41、,51 3,05 3,45 4,60 5,64 Recess no. 0 1 2 3 4 m ref. 1,9 2,7 2,9 4,1 4,6 4,8 6,6 8,7 9,6 min. 0,9 1,25 1,4 1,6 2,1 2,3 2,8 3,9 4,8 Type H Penetration depth max. 1,2 1,55 1,8 2,1 2,6 2,8 3,3 4,4 5,3 Recess no. 0 1 2 3 4 m ref. 1,9 2,5 2,8 4 4,4 4,6 6,3 8,5 9,4 min. 0,95 1,22 1,48 1,61 2,06 2,27 2,73 3
42、,87 4,78 Cross recess Series 2d (shallow) Type Z Penetration depth max. 1,20 1,47 1,73 2,05 2,51 2,72 3,18 4,32 5,23 BS EN ISO 7046-2:2011ISO 7046-2:2011(E) 4 ISO 2011 All rights reservedTable 1 (continued) Dimensions in millimetres Thread, d M2 M2,5 M3 (M3,5) M4 M5 M6 M8 M10 laenom. min. max. 3 2,8
43、 3,2 4 3,76 4,24 5 4,76 5,24 6 5,76 6,24 8 7,71 8,29 Range 10 9,71 10,29 12 11,65 12,35 (14) 13,65 14,35 of 16 15,65 16,35 20 19,58 20,42 25 24,58 25,42 preferred 30 29,58 30,42 35 34,5 35,5 40 39,5 40,5 45 44,5 45,5 lengths 50 49,5 50,5 (55) 54,05 55,95 60 59,05 60,95 aSizes in brackets should be a
44、voided if possible. bP is the pitch of the thread. cSee ISO 7721. dIn accordance with ISO 7721-2. eScrews with nominal lengths above the bold, discontinuous line are threaded up to the head; b = l (k + a). BS EN ISO 7046-2:2011ISO 7046-2:2011(E) ISO 2011 All rights reserved 54 Specifications and ref
45、erence International Standards See Table 2. Table 2 Specifications and reference International Standards Material Steel Stainless steel Non-ferrous metal Tolerance class 6g Thread International Standard ISO 261, ISO 965-2 Property class 8.8 A2-70 CU2, CU3aMechanical property International Standard I
46、SO 898-1 ISO 3506-1 ISO 8839 Product grade A Tolerance International Standard ISO 4759-1 Cross recess International Standard ISO 4757 As processed Requirements for electroplating are specified in ISO 4042. Requirements for non-electrolytically applied zinc flake coatings are specified in ISO 10683.
47、Requirements for passivation are specified in ISO 16048. Requirements for electroplating are specified in ISO 4042. Finish Coating Additional requirements or other finishes or coatings shall be agreed between the supplier and the purchaser. Surface integrity Limits for surface discontinuities are sp
48、ecified in ISO 6157-1 and ISO 6157-3. Acceptability Acceptance inspection is specified in ISO 3269. aAt the manufacturers discretion. 5 Designation EXAMPLE 1 A cross-recessed countersunk flat head screw, with thread M5, nominal length l = 20 mm, property class 8.8 and cross recess type Z, penetratio
49、n depth series 1 or 2 at the manufacturers discretion is designated as follows: Countersunk head screw ISO 7046-2 - M5 20 - 8.8 - Z EXAMPLE 2 If, in special cases, one of the two series is wanted, the number of the series should be included in the designation as follows: Countersunk head screw ISO 7046-2 - M5 20 - 8.8 - Z1 BS EN ISO 7046-2:2011ISO 7046-2:2011(E) 6 ISO 2011 All rights reservedBib
