1、BRITISH STANDARD BS3551:1962 Incorporating amendment issued August1963 (PD4964) Specification for Alloy steel shackles UDC 621.885.7:669.15BS3551:1962 This British Standard, having been approved by the MechanicalEngineering IndustryStandards Committee and endorsed by the Chairman ofthe Engineering D
2、ivisional Council, was published under theauthority of the General Council on 22nd October1962 BSI 07-1999 The following BSI references relate to the work on this standard: Committee reference MEE/12 Draft for comment AB(MEE)936 ISBN 0 580 35090 8 Co-operating organizations The Mechanical Engineerin
3、g Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: Admiralty* Engineering Equipment Users Association* Air Ministry Gas Council Associated Offic
4、es Technical Committee* High Commission of India Association of Consulting Engineers Institute of Marine Engineers* (Incorporated) Institute of Petroleum Association of Mining Electrical and Institution of Civil Engineers Mechanical Engineers Institution of Gas Engineers British Chemical Plant Manuf
5、acturers Institution of Heating and Ventilating Association Engineers British Compressed Air Society Institution of Mechanical Engineers* British Electrical and Allied Manufacturers Institution of Mechanical Engineers Association (Automobile Division) British Engineers Association* Institution of Pr
6、oduction Engineers British Gear Manufacturers Association Locomotive and Allied Manufacturers British Internal Combustion Engine Association of Great Britain Manufacturers Association Machine Tool Trades Association British Iron and Steel Federation* Ministry of Labour (Factory Inspectorate)* Britis
7、h Railways, the British Transport Ministry of Power* Commission* Ministry of Public Buildings and Works Crown Agents for Oversea Governments Ministry of Transport* and Administrations National Coal Board* D.S.I.R. National Engineering Laboratory* National Physical Laboratory (D.S.I.R.)* Electricity
8、Council, The Generating Board and Radio Industry Council the Area Boards in England and Wales War Office* The Government departments and scientific and industrial organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entruste
9、d with the preparation of this standard: Association of Crane Makers London Transport Executive, The British Association of Lifting Tackle Makers Transport Commission British Constructional Steelwork Association Machine-made Chain Manufacturers Chain Type2, a screwed pin with circular head; Type3, a
10、 bolt with a circular head, hexagon nut and split cotter pin; and Type4, a plain cylindrical pin with circular head and forelock. Alloy steel pins can be identified by the special flats on each side of the circular head of each type. The mechanical properties of the materials from which alloy steel
11、shackles are made are comparable to those of the material used for the terminal components of alloy steel chain slings to BS3458 3) . In view of the importance of correct heat treatment, particular attention is drawn to the necessity for strict supervision and control when heat treating the shackles
12、. Whilst mild steel shackles, etc., may be galvanized or sherardized, too little is known about these finishes on alloy steel shackles to recommend their use at the present time. In accordance with British Standard practice, the term “British Standard alloy steel shackle” refers only to the shackles
13、 listed in the tables of this standard. The specification introduces a term for shackles complying with its requirements except for those relating to the tables of dimensions (see Clause3). Each type of shackle in Table 1 and Table 2 is composed of a series of geometrically similar shackles, all the
14、 dimensions with the exception of the pins in the smaller sizes (see Figure7), being proportional to the square root of the safe working load, W. 1) BS825, “Mild steel shackles”. 2) BS3032, “Higher tensile steel shackles”. 3) BS3458, “Alloy steel chain slings”.BS3551:1962 BSI 07-1999 iii The dee sha
15、ckle (Table 1) has moderate internal clearances in the body and jaw, and for a given size, a safe working load of approximately twice that of the mild steel large dee to BS825, and one-and-a-half times that of the higher tensile steel large dee to BS3032. These shackles are particularly suitable whe
16、n the pin must be fitted into a hole of limited diameter. The shackles are also suitable for use with the eyes and bodies of hooks, eyebolts, egg links, wire rope thimbles, etc., and for the head fittings of blocks. The bow shackle (Table 2) has moderate internal clearances in the body and jaw, and
17、for a given size, a safe working load of approximately twice that of the mild steel large bow to BS825, and one-and-a-half times that of the higher tensile steel large bow to BS3032. These shackles are particularly suitable when the pin must be fitted into a hole of limited diameter. The shackles ar
18、e also suitable for use with the eyes and bodies of hooks, eyebolts, egg links, wire rope thimbles, etc., and for the head fittings of blocks. Specimen shackles representative of the dee and bow shackles specified, have been subjected to static proof loads (twice the safe working load), with satisfa
19、ctory results. The safe working loads specified are for normal conditions of service. For specially hazardous conditions, it is desirable that the safe working loads should be reduced. The committee entrusted with the preparation of the standard desires to record its indebtedness to the Department o
20、f Scientific and Industrial Research for help in the theoretical and experimental investigations on which this standard is based. NOTE 1Metric equivalents have been given in Appendix D. The figures in British units are to be regarded as the standard. The conversions are approximate. More accurate co
21、nversions should be based on the tables in BS350, “Conversion factors and tables”. NOTE 2In place of the customary, but incorrect, use of the pound and kilogramme as units of force, the units called ton-force (abbreviation tonf) and kilogramme-force (abbreviation kgf) have been used in this standard
22、. These are the forces which, when acting on a body of mass one pound or one kilogramme respectively, give it an acceleration equal to that of standard gravity. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for t
23、heir correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi toiv, pages1 to16, an inside back cover and a back cover. This standard has been updated (see
24、copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.iv blankBS3551:1962 BSI 07-1999 1 1 Scope This specification covers shackles in alloy steel. Material, heat-treatment, workmanship, finish, screw threads, proof loading,
25、marking and certification are specified. Tables of dimensions for dee and bow shackles are given. Design requirements are laid down for special (or unscheduled) shackles whose dimensions differ from those given in these tables. 2 Types of shackle The shackle comprises body and pin, or body and bolt
26、with nut. The body shall be one of the following types as specified by the purchaser: Dee: Table 1, Figure 1; Bow: Table 2, Figure 2. The pin shall be one of the following types: Type1. Screwed pin with eye and collar, Figure 3; Type2. Screwed pin with circular head, Figure 4; Type3. Bolt with circu
27、lar head, hexagon nut and split cotter pin, Figure 5; Type4. Plain cylindrical pin with circular head and forelock, Figure 6. NOTEAlloy steel pins can be identified by the special flats on each side of the circular head of each type. 3 Special shackles Special (or unscheduled) shackles whose dimensi
28、ons differ from those in Table 1 and Table 2, may be designated “Special shackles to BS3551”, subject to the following conditions: a) The diameter of the material of the body shall be not less than inch, nor exceed4 inches. b) The diameter of the pin shall be not less than ) inch, nor exceed4 inches
29、. c) The safe working load of the shackle shall not exceed the least value obtained from formulae (1), (2a) or (2b), given in Appendix B. d) When the shackle body is less than1 inch in size, the diameter (D) of the pin, obtained from formula(1), shall be multiplied by the correction factor obtained
30、from Figure7. e) In no case shall the pin diameter (D), be less than the body diameter (d). f) In no case shall the measurement across the eye (e), be less than2D. 4 Material, heat treatment, hardness a) Quality of steel. The bodies and pins of the shackles shall be manufactured from steel produced
31、by the open hearth or electric process. The steel shall be free from piping, harmful segregation and other defects. Billets and bars for forging shall be rough machined, chipped, ground or otherwise prepared to remove surface defects which might produce defects in the forgings or drop forgings made
32、therefrom. b) Chemical composition of steel. The chemical composition shall conform to one of the following types: Element Steel A a Steel B a Steel C min. max. min. max. min. max. Carbon Silicon Manganese Nickel Chromium Molybdenum Sulphur Phosphorus percent 0.30 0.10 1.30 0.20 percent 0.40 0.35 1.
33、80 0.35 0.050 0.050 percent 0.35 0.10 1.20 0.50 0.30 0.15 percent 0.45 0.50 1.50 1.00 0.60 0.25 0.050 0.050 percent 0.18 0.10 0.70 0.40 0.40 0.15 percent 0.23 0.35 1.00 0.70 0.70 0.25 0.050 0.050 Forelocks and nuts may be made of mild steel. a The steels Types A and B are respectively equivalent to
34、those of En.16 and En.100 of BS970 b . b BS970, “Wrought steels. En series”.BS3551:1962 2 BSI 07-1999 c) Heat treatment of bodies and pins. The bodies and pins shall, before proof loading, be heat treated as follows: Steel A and B. Harden by quenching in oil from830/860 C, followed by tempering betw
35、een 550 C and660 C. Steel C. Harden by quenching in oil or water from 850/890 C, followed by tempering between 500 C and600 C. d) Hardness of bodies and pins. The bodies and pins of the shackles after heat treatment shall have a Brinell hardness number between248 and302. Where practicable, the hardn
36、ess testing shall be carried out in accordance with BS240-1 4) , using a10mm diameter ball, and a load of3000kg. The surface on which the impression is to be made shall be obtained by filing, grinding, or smooth machining. Suitable precautions should be taken to ensure that the surface tested is rep
37、resentative of the material, and that its hardness is not affected by decarburization, carburization, or by the method used for its preparation. If another method is employed, conversion shall be made in accordance with BS860 5) . 5 Size The size of the shackle shall be the nominal diameter (d) of t
38、he material from which the shackle body is made (See Figure 1 and Figure 2). 6 Form and dimensions The form and dimensions of the body and pin shall be in accordance with Figure 1 to Figure 6, and Table 1 and Table 2 (except for “Special shackles”, Clause3). 7 Tolerances on dimensions The dimensions
39、 of the bodies (with the exception of the pin diameters and pin holes), shall be not less than the nominal dimensions and shall not exceed them by more than5per cent. The diameters of the pins are subject to the following tolerances: The diameters of the pin holes in the bodies of the shackles are s
40、ubject to the following tolerances: 8 Workmanship The pin shall be forged and machined, or machined from the bar. The screwed portion of the pin shall be concentric with the plain portion. When pins of Types1 and2 are screwed home, not more than one half thread shall be visible between the jaws of t
41、he shackle. The body shall be a solid forging without weld. Pin or bolt holes in the body shall be drilled from the solid, or hot-pierced to two thirds finished size, and drilled or bored in axial alignment at one setting central to the outside diameter of the eyes. 4) BS240, “Method for Brinell har
42、dness test”, Part1, “Testing of metals”. 5) BS860, “Tables of approximate comparison of hardness scales”. up to and including2 inch diameter pin 0.003 in to0.010 in; over2 inch diameter pin 0.005 in to0.020 in. up to and including 3 / 4inch diameter hole + 1 / 32in 0 in; 7 / 8inch, up to and including1 3 / 4inch diameter hole + 3 / 64in0 in; over1 3 / 4inch diameter hole + 1 / 16in0 in.
