1、BRITISH STANDARD BS 7670-1: 1993 Incorporating Amendment No. 1 Steel nuts and bolts for resistance projection welding Part 1: Specification for dimensions and properties UDC 621.882:669.14.018:621.791.76BS7670-1:1993 This British Standard, having been prepared under the direction of the General Mech
2、anical Engineering Standards Policy Committee, was published under the authority of the Standards Board and comes into effecton 15September1993 BSI 01-1999 The following BSI references relate to the work on this standard: Committee reference GME/9 Draft for comment 92/82393 DC ISBN 0 580 21856 2 Com
3、mittees responsible for this British Standard The preparation of this British Standard was entrusted by the General Mechanical Engineering Standards Policy Committee (GME/-) to Technical Committee GME/9, upon which the following bodies were represented: BEAMA Ltd. British Constructional Steelwork As
4、sociation Ltd. British Industrial Fasteners Federation British Railways Board British Steel Industry British Steel Industry (Wire Section) Gauge and Tool Makers Association Society of Motor Manufacturers and Traders Ltd. Washer Manufacturers Association of Great Britain The following bodies were als
5、o represented in the drafting of the standard, through subcommittees and panels: Defence Manufacturers Association General Municipal Boilermaker and Allied Trades Union Screw Thread Tool Manufacturers Association Society of British Aerospace Companies Ltd. Amendments issued since publication Amd. No
6、. Date Comments 8215 July 1994 Indicated by a sideline in the marginBS7670-1:1993 BSI 01-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 References 1 3 Definitions 1 4 Weld bolts 1 5 Weld nuts 1 Figure 1 Dimensions of weld bolts 2 Figure 2 Dimensions of square
7、weld nuts 3 Figure 3 Dimensions of hexagonal weld nuts 4 Table 1 Dimensions of weld bolts 2 Table 2 Characteristics of weld bolts 3 Table 3 Dimensions of square weld nuts 4 Table 4 Dimensions of hexagonal weld nuts 5 Table 5 Characteristics of weld nuts 5 List of references Inside back coverBS7670-1
8、:1993 ii BSI 01-1999 Foreword This Part of BS7670 has been prepared under the authority of the General Mechanical Engineering Standards Policy Committee. It is one Part of a standard for steel nuts and bolts for resistance projection welding. BS 7670-2 provides a specification for the welding proces
9、ses and conditions applicable to weld bolts and nuts for resistance projection welding. 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
10、itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be
11、 indicated in the amendment table on theinside front cover.BS7670-1:1993 BSI 01-1999 1 1 Scope This Part of BS 7670 specifies the general dimensions, tolerances, materials and mechanical properties both for imperial weld nuts threaded7/1620UNF2B and metric weld nuts and weld bolts with nominal threa
12、d diameters from M3toM12inclusive. The weld bolts have circular heads with three projections and the nuts are square with four projections or hexagonal with three projections for projection welding. 2 References 2.1 Normative references This Part of BS7670 incorporates, by reference, provisions from
13、 specific editions of other publications. These normative references are cited at the appropriate points in the text and the publications are listed on the inside back cover. Subsequent amendments to, or revisions of, any of these publications apply to this Part of BS7670 only when incorporated in i
14、t by updating or revision. 2.2 Informative references This Part of BS7670 refers to other publications that provide information or guidance. Editions of these publications current at the time of issue of this standard are listed on the inside back cover, but reference should be made to the latest ed
15、itions. 3 Definitions For the purposes of this Part of BS 7670, the definitions given in BS 499-1:1991 apply. 4 Weld bolts 4.1 Dimensions The dimensions of weld bolts shall be as given inFigure 1 andTable 1. The electrode contact area d f min. shall be flat, smooth and free from surface projections.
16、 4.2 Characteristics The materials, tolerances and mechanical properties shall be as given inTable 2. 4.3 Designation When designating weld bolts for the purpose of an enquiry or order, the following information shall be given: a) general product description, i.e.weld bolt; b) the number of this Bri
17、tish Standard, i.e.BS7670-1; c) the letter M indicating that the product is ISOmetric; d) the nominal size (thread diameter) of the product in millimetres (d inFigure 1); e) the nominal length in millimetres (l in Figure 1); f) the property class; g) details of the coating (if required) and the rele
18、vant British Standard where applicable. Example. The designation of a weld bolt, with a thread diameter of 8mm, and a nominal length of25mm, conforming to class4.8, is as follows: Weld bolt BS7670-1, M8 25 4.8 5 Weld nuts 5.1 Dimensions The dimensions of square weld nuts shall be as given inFigure 2
19、 andTable 3. The dimensions of hexagonal weld nuts shall be as given inFigure 3 andTable 4. 5.2 Characteristics The materials, tolerances and mechanical properties shall be as given inTable 5.BS7670-1:1993 2 BSI 01-1999 Table 1 Dimensions of weld bolts NOTEDimension l is the designated nominal lengt
20、h (see 4.3). Figure 1 Dimensions of weld bolts Dimensions in millimetres Thread size, d M3 M4 M5 M6 M8 M10 M12 Thread pitch 0.5 0.7 0.8 1.0 1.25 1.5 1.75 a max. 1.25 1.75 2.0 2.5 3.13 3.75 4.38 d k max. 6.37 8.45 10.45 12.55 16.55 20.65 24.65 min. 5.63 7.55 9.55 11.45 15.45 19.35 23.35 d f min. 5.13
21、 7.05 9.05 10.95 14.95 18.85 22.85 d 1 max. 4.98 6.48 8.08 9.58 12.70 15.70 18.70 min. 4.50 6.00 7.50 9.00 12.00 15.00 18.00 d 2 max. 1.15 1.45 1.75 2.05 2.65 3.25 3.90 min. 0.90 1.20 1.50 1.80 2.40 3.00 3.60 V max. 0.55 0.70 0.85 1.00 1.30 1.60 1.90 min. 0.35 0.50 0.65 0.80 1.10 1.40 1.70 k max. 1.
22、32 1.72 2.12 2.52 3.35 4.15 4.95 min. 1.07 1.47 1.87 2.27 3.05 3.85 4.65 r max. 0.40 0.40 0.50 0.60 0.80 0.80 0.80 NOTETolerances conform to BS6322-1:1982.BS7670-1:1993 BSI 01-1999 3 Table 2 Characteristics of weld bolts Characteristic Requirement Material Steel with a carbon content not greater tha
23、n0.23% Thread tolerance Conforming to class 6g of BS3643-1:1981 and BS 3643-2:1981 Mechanical properties a Conforming to material property class4.8,5.8 or8.8 of BSEN 20898-1:1992, test programme B b Permissible dimensional deviations and deviations of form Conforming to product grade A of BS6322-1:1
24、982 Finish As processed, with a lubricant, but free from scale and excessive oxide, as rolled, unless otherwise agreed between the purchaser and supplier c Acceptability In accordance with BS6587:1985 a Both before and after welding. b The material property class shall be marked on the bolts by the
25、indented method only. c Alternative surface finishes (e.g.electroplating) may be applied, if agreed between the purchaser and supplier. Some surface finishes are unsuitable for welding. NOTEThe internal form of the weld projections may be radiused at the discretion of the supplier. Figure 2 Dimensio
26、ns of square weld nutsBS7670-1:1993 4 BSI 01-1999 Table 3 Dimensions of square weld nuts NOTEThe internal form of the weld projections may be radiused at the discretion of the supplier. Figure 3 Dimensions of hexagonal weld nuts Dimensions in millimetres Thread size, d 1 M4 M5 M6 M8 M10 20UNF2B M12
27、Thread pitch 0.7 0.8 1.0 1.25 1.5 1.75 b max. 0.95 1.15 1.35 1.65 2.0 2.2 2.2 min. 0.65 0.85 1.05 1.35 1.6 1.8 1.8 d 2 max. 5.18 6.18 7.72 10.22 12.77 13.77 13.77 min. 5 6 7.5 10 12.5 13.5 13.5 d 3 max. 4.2 5.25 6.3 8.4 10.5 11.7 12.6 e min. 9 12 13 18 22 25 25 h max. 0.7 0.9 0.9 1.1 1.3 1.5 1.5 min
28、. 0.5 0.7 0.7 0.9 1.1 1.3 1.3 m max. 3.5 4.2 5 6.5 8 9 9.5 min. 3.2 3.9 4.7 6.14 7.64 8.64 9.14 s max. 7 9 10 14 17 19 19 min. 6.64 8.64 9.64 13.57 16.57 18.48 18.48 7 16 -BS7670-1:1993 BSI 01-1999 5 Table 4 Dimensions of hexagonal weld nuts Table 5 Characteristics of weld nuts Dimensions in millime
29、tres Thread size, d 1 M3 M4 M5 M6 M8 M10 20 UNF2B M12 Thread pitch 0.5 0.7 0.8 1.0 1.25 1.5 1.75 b max. 1.0 1.0 1.0 1.12 1.25 1.55 1.55 1.55 min. 0.6 0.6 0.6 0.68 0.75 0.95 0.95 0.95 d 2 max 4.68 6.18 7.22 8.22 10.77 12.77 13.77 15.07 min. 4.5 6 7 8 10.5 12.5 13.5 14.8 d 3 max. 3.15 4.2 5.25 6.3 8.4
30、 10.5 11.7 12.6 d 4 max. 4.47 5.97 6.96 7.96 10.45 12.45 13.45 14.75 min. 4.395 5.895 6.87 7.87 10.34 12.34 13.34 14.64 e min. 8.15 9.83 10.95 12.02 15.38 18.74 20.91 20.91 h 1 max. 0.55 0.65 0.7 0.75 0.9 1.15 1.4 1.4 min. 0.45 0.55 0.6 0.6 0.75 1 1.2 1.2 h 2 max. 0.25 0.35 0.4 0.4 0.5 0.65 0.8 0.8
31、min. 0.15 0.25 0.3 0.3 0.35 0.5 0.6 0.6 m max. 3 3.5 4 5 6.5 8 10 10 min. 2.75 3.2 3.7 4.7 6.14 7.64 9.64 9.64 s max. 7.5 9 10 11 14 17 19 19 min. 7.28 8.78 9.78 10.73 13.73 16.73 18.67 18.67 Characteristic Requirement Material Steel with a carbon content not greater than 0.23% Thread tolerance ISO
32、metric Conforming to class 6H of BS 3643-1:1981 and BS 3643-2:1981 Unified Conforming to class 2B of BS1580-1:1962 b) the number of this British Standard, i.e.BS7670-1; c) the letter M indicating that the product is ISOmetric; d) the nominal size (thread diameter) of the product in millimetres; e) t
33、he property class; f) details of the coating (if required) and the relevant British Standard where applicable. Example. The designation of a square weld nut with a thread diameter of8mm, conforming to property class6, is as follows: Square weld nut BS 7670-1, M86. 5.3.2 20 UNF 2B weld nuts When desi
34、gnating 20 UNF 2B weld nuts for the purpose of an enquiry or order, the following information shall be given: a) general product description, e.g.hexagonal weld nut; b) the number of this British Standard, i.e.BS7670-1; c) the thread size, i.e. 20 UNF 2B; d) the property class; e) details of the coa
35、ting (if required) and the relevant British Standard where applicable. Example. The designation of a hexagonal weld nut with a 20 UNF 2B thread, conforming to property class 4, is as follows: Hexagonal weld nut BS 7670-1, 20UNF 2B 4. 7 16 - 7 16 - 7 16 - 7 16 - 7 16 -BS7670-1:1993 BSI 01-1999 List o
36、f references (see clause2) Normative references BSI standards publications BRITISH STANDARDS INSTITUTION, London BS 499, Welding terms and symbols. BS 499-1:1991, Glossary for welding, brazing and thermal cutting. BS 1580, Specification for Unified screw threads. BS 1580-1:1962 & BS 1580-2:1962, Dia
37、meters in and larger. BS 3643, ISO metric screw threads. BS 3643-1:1981, Principles and basic data. BS 3643-2:1981, Specification for selected limits of size. BS 6322, Tolerances for fasteners. BS 6322-1:1982, Specification for tolerances of bolts, screws and nuts with thread diameters$ 1.6mmand# 15
38、0mm and product grades A, B and C. BS 6587:1985, Method of acceptance inspection for fasteners. BS EN 20898, Mechanical properties of fasteners. BS EN 20898-1:1992, Bolts, screws and studs. BS EN 20898-2:1992, Nuts with specified proof load values. Informative references BSI standards publications B
39、RITISH STANDARDS INSTITUTION, London BS 7670, Steel nuts and bolts for resistance projection welding. BS 7670-2, Welding conditions 1)2) . 1) In preparation. 2) Referred to in foreword only. 1 4 -BSI 389 Chiswick High Road London W4 4AL | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
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