1、BSI BSr4Lb: PARTSA 82 Lb2Ybb 0052921 9 BS4168:Part8: 1982 UDC 621.882.215.6.091.6 (Reprinted, incorporating Amendment No. 1 ) O British Standards Institution. No part of this publication may be photocopied or otherwise reproduced without the prior permission in writing of BSI, British Standard Hexag
2、on socket screws and wrench keys: metric series 0 Part 8. Specification for hexagon socket countersunk head screws Vis six pans creux et cls mles pour six pans: srie mtrique Partie 8. Vis tte fraise six pans creux - Spcifications I nnensechskantschrauben und Steckschlssel: metrische Reihe Teil 8. In
3、nensechskantschrauben mit Senkkopf British Standards Institution BSI BS*qLb8: PAFT*8 82 Lb24b67 0052722 O W BS 4168 : Part 8 : 1982 Contents Page Foreword Inside front cover Tables Cooperating organizations Back cover 1. Dimensions Specification 1. Scope 1 Figures 2. References 1. Countersunk screws
4、 3. Dimensions and surface detail 2. Specifications and reference standards 2. Flushnessgauge 4. Specif ications and reference standards 5, Designation 4 4 Compliance with a British Standard does not of itself confer immunity from legal obligations. Foreword This British Standard has been prepared u
5、nder the direction of the Mechanical Engineering6tandards Committee and forms part of the revision of BS 4168 : 1967. It is one of a series of specifications, of which the full list is as follows: Part 1, Specification for hexagon socket head cap screws Part 2. Specification for hexagon socket set s
6、crews with Part 3. Specification for hexagon socket set screws with Part 4. Specification for hexagon socket set screws with Part 5. Specification for hexagon socket set screws with Part 6. Specification for hexagon socket button head Part 7. Specification for hexagon socket shoulder flat point cone
7、 point dog point cup point screws screws Page 3 4 2 2 Part 8. Specification for hexagon socket countersunk head screws *Part 9. Wrench keys This Part of this standard is based on the work in progress in ISO/TC 2 Fasteners and it also formed the United Kingdom proposal to ISO/TC 2. If, in special cas
8、es, requirements other than those listed in this standard are necessary, it is recommended that they should be selected from the standards referred to in clause 4. Although the tolerances on some features specified in this standard differ from those specified in BS 4168 : 1967, screws complying with
9、 this standard are generally inter- changeable with screws complying with BS 4168 : 1967. *In course of preparation, BSI BS*4Lb: PART* 192 m Lb24667 0052723 2 BS 4168 : Part 8 : 1982 o British Standard Hexagon socket screws and wrench keys: metric series Part 8. Specification for hexagon socket coun
10、tersunk head screws 1. Scope This Part of BS 4168 specifies requirements for hexagon socket countersunk head screws with IS0 metric threads and diameters from 3 mm up to and including 20 mm. NOTE. Particular attention is drawn to the note in clause 4, concerning the limitation on ultimate tensile st
11、rength. 2. References The titles of the standards publications referred to in this standard are listed on the inside back cover. 3. Dimensions and surface detail The dimensions and surface detail of the countersunk head screws shall be in accordance with figure 1 and table 1. Figure 2 illustrates a
12、suitable gauge for the control of the flushness tolerance, e (o O 1 i BSI BS*:4Lb8: PART%8 82 E Lb24bb 005292Lt i.I E BS 41 68 : Part 8 : 1982 90 92 Point to be chamfered or for sizes M4 and below as rolled L Edge of head to be flat or rounded NOTE, I, and I, are the shank length and the grip length
13、 respectively. 120 min. Permissible alternative form of socket NOTE. For broached sockets which are at the maximum limit of size, the overcut resulting from drilling shall not exceed 20 % of the length of any flat of the socket. Figure I. Countersunk screws 90 I A slight rounding or countersink at t
14、he mouth of the socket is permissible Figure 2. Flushness gauge 2 BS 4168 : Part 8 : 1982 a“ 3 BS 4168 : Part 8 : 1982 4. Specif ications and reference standards 4.1 The countersunk head screws shall be manufactured in accordance with the specifications in table 2 and 4.2 and the relevant reference
15、standards as noted. 4.2 When full size screws are loaded with the head supporte on a suitable collar using the type of testing fixture illustrated in figure 2 of BS 6104 : Part 1 : 1981 they shall withstand the loads given below without fracture. Thread size, d M3 M4 M5 M6 M8 MIO MI2 M 141 MI6 M 20
16、Test load N 5 200 9 100 14 800 20 900 38 100 60 300 87 700 120 O00 163 O00 255 O00 NOTE, If tested to failure, the fracture may occur in the threaded section, the head or at the head shank junction. Table 2. Specif ications and reference standards Material Thread Tolerance Standard Class Standard Pr
17、oduct grade British Standard Mechanical properties Tolerances Discontinuities Finish Acceptability Steel 5969 BS 3643 12.9 . 6s 6104 : Part 1 A BS 6322 : Part 1 2 BS Black oxide (thermal or chemical). Requirements for electroplating are covered in BS 3382. If different electroplating requirements ar
18、e needed for other finishes they should be negotiated between customer and supplier. For acceptance precedure see BS 6587 Because of their head configurations, Countersunk head screws may not meet the minimum ultimate tensile load for properr/ class 12.9, specified in table 6 of BS 6104 : Part 1 : 1
19、981, when tested in accordance with test programme B. They are never- theless required to meet the other material and property requirements for property class 12.9 in BS 6104 : Part 1. Waiting the publication of IS0 6157/3. 5. Designation When designating countersunk head screws, for the purpose of
20、an enquiry or order, the information as the following example shall be given. Hexagon socket countersunk head screw with thread sized = MI2 and nominal length 1 = 40 mm: Hexagon socket countersunk head screw BC 4168 MI2 X 40 4 O O e BSI BSSqlbB: PARTS8 Bi2 = 1624bb9 005!q27 T Standards publications
21、referred to BS 3382 BS 3643 BS 61 o4 BS 6322 Tolerances for fasteners Electr plated coatings on threaded components IS0 metric screw threads Mechanical properties of fasteners Part 1 Specification for bolts, screws and studs Part 1 Specification for tolerances of bolts, screws and nuts with thread d
22、iameters 1.6 mm and grades A, B and C Method of acceptance inspection for fasteners 150 mm and product BS 6587 O O - BSI BS*4Lb8: PART*8 82 W lib24669 0052428 L BS4168:Part8: 1982 This British Standard, having been prepared under the direction of the Mechanical Engineering Standards committee, was p
23、ublished under the authority of the Board of BSI and comes into effect on 31 August 1982. O British Standards Institution, 1982 ISBN O 580 12796 6 The following BSI references relate to the work on this standard: Committee reference GME/9 (formerly MEE/6O) Draft for comment 81175323 DC British Stand
24、ards Institution. Incorporated by Royal Charter, BSI is the independent national body for the preparation of British Standards. It is the UK member of the International Organization for Standardization and UK sponsor of the British National Committee of the International Electrotechnical Commission.
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27、urse of implenienting the standard, of necessary details such as symbols and size, type or grade designations. Enquiries should be addressed to the Publications Manager, BSI, Linford Wood, Milton Keynes MK14 6LE. The number for telephone enquiries is 0908 220022 and for telex 825777. Contract requir
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30、ction at Milton Keynes, telephone 0908 221 166, telex 825777. Information on all BSI publications is in the BSl Catalogue, supplemented each month by BSI News which is available to subscribing members of BSI and gives details of new publications, revisions, amendments and withdrawn standards. Any pe
31、rson who, when making use of a British Standard, encounters an inaccuracy or ambiguity, is requested to notify BSI without delay in order that the matter may be investigated and appropriate action taken. Cooperating organizations The Mechanical Engineering Standards Committee, under whose direction
32、this Brltish Standard was prepared, consists of representatives from the following: Associated Offices Technical Committee Association of Consulting Engineers Association of Hydraulic Equipment Manufacturers Association of Mining Electrical and Mechanical Engineers British Compressed Air Society Bri
33、tish Gas Corporation British Gear Manufacturers Association British Pump Manufacturers Association British Steel Corporation Chartered Institution of Building Services Crown Agents for Oversea Governments and Administrations Department of Industry (Mechanical Engineering) Department of the Environme
34、nt (PSA) Department of Trade (Marine Division) Department of Transport Electricity Supply Industry in England and Wales Energy Industries Council Engineering Equipment Users Association Federation of Manufacturers of Construction Equipment and *British Electrical and Allied Manufacturers Association
35、 (BEAMA) *British Internal Combustion Engine Manufacturers Association *British Steel Industry *Department of Industry (National Engineering Laboratory) Cranes Am end ment s issued si nce pub I i ca t io n Health and Safety Executive Institution of Gas Engineers Institution of Mechanical Engineers I
36、nstitution of Plant Engineers *lnstltution of Production Engineers Lloyds Register of Shipping London Transport Executive Machine Tool Industry Research Association *Ministry of Defence *National Coal Board Oil Companies Materiais Association Process Plant Association *Society of Motor Manufacturers
37、 and Traders Limited *Telecommunication Engineering and Manufacturlng Association (TEMA) Water-tube Boilermakers Association The organizations marked with an asterisk In the above list, together with the following, were directly represented on the Technical Committee entrusted with the preparation o
38、f this British Standard: British Constructional Steelwork Association British Industrial Fasteners Federation British Railways Board British Steel Industry (Wire Section) Electronic Engineering Association Federation of British Hand Tool Manufacturers Gauge and Tool Makers Association Washer Manufacturers Association of Great Britain Amd. No. 1 Date of issue I Text affected 5659 I August 1987 I Indicated by a line in the margin British Standards Institution 2 Park Street London WIA 2BS . Telephone 01-629 9000 - Telex 266933 8901 -3-0.3k-B GMEl9
