BS 4395-1

British StandardA single copy of this British Standard is licensed to Akin Koksal Licensed Copy: Akin Koksal, Bechtel Ltd, 09 December 2002, Uncontrolled Copy, (c) BSI 09 December 2002 This is an uncontrolled copy. Ensure use of the most current version of this document by searching British Standards Online at bsonline.techindex.co.uk BRITISH STANDARD BS 4395-1: 1969 Incorporating Amendment Nos. 1 and 2 Specification for High strength friction grip bolts and associated nuts and washers for structural engineering metric series — Licensed Copy: Akin Koksal, Bechtel Ltd, 09 December 2002, Uncontrolled Copy, (c) BSI Part 1: General Grade UDC 621.882:624.014.2:693.8 M. Army Department* British Steel Industry* Ministry of Power Crown Agents for Oversea Governments and Ministry of Public Building and Works* Administrations Ministry of Technology Department of Employment and Productivity Ministry of Technology — National Engineering (H. Factory Inspectorate) Laboratory* Licensed Copy: Akin Koksal. No. were directly represented on the committee entrusted with the preparation of this British Standard: Association of Hydraulic Equipment Institute of Iron and Steel Wire Manufacturers Manufacturers Ministry of Defence. Petroleum Equipment Washer Manufacturers’ Association of Great Electronic Engineering Association Britain Fasteners and Turned Parts Institute Individual Manufacturer This British Standard. consists of representatives from the following Government departments and scientific and industrial organizations: Associated Offices’ Technical Committee Institute of Marine Engineers Association of Consulting Engineers Institution of Civil Engineers Association of Mining Electrical and Institution of Gas Engineers Mechanical Engineers Institution of Heating and Ventilating Board of Trade Engineers British Chemical Plant Manufacturers’ Institution of Mechanical Engineers Association Institution of Mechanical Engineers British Compressed Air Society (Automobile Division) British Electrical and Allied Manufacturers’ Institution of Production Engineers* Association* Locomotive and Allied Manufacturers’ British Gear Manufacturers’ Association Association of Great Britain* British Internal Combustion Engine London Transport Board Manufacturers’ Association Machine Tool Trades Association* British Mechanical Engineering Confederation Ministry of Defence British Pump Manufacturers’ Association Ministry of Defence. was published under the authority of the Executive Board on 19 February 1969 Amendments issued since publication © BSI 03-1999 Amd. 09 December 2002. the Central Electricity Ministry of Transport Generating Board and the Area Boards in National Coal Board* England and Wales* National Physical Laboratory (Ministry of Engineering Equipment Users’ Association* Technology Gas Council Royal Institute of British Architects The Government departments and scientific and industrial organizations marked with an asterisk in the above list. together with the following. Society of Motor Manufacturers and Council of British Manufacturers of Traders Ltd. under whose supervision this British Standard was prepared. Date Comments The following BSI references relate to the work on this 1841 October 1975 standard: Committee references MEE/60. having been approved by the Mechanical Engineering Industry Standards Committee. Bechtel Ltd. 2198 January 1977 Indicated by a sideline in the margin MEE/60/11 Draft for comment 67/31503 ISBN 580 00432 5 . Uncontrolled Copy. Navy Department Black Bolt and Nut Association of Great Britain Post Office Britain Precision Bolt and Nut Institute British Railways Board Rolled Thread Screw Association British Constructional Steelwork Association Scientific Instrument Manufacturers’ British Cycle and Motor Cycle Industries Association Association Ltd. BS 4395-1:1969 Co-operating organizations The Mechanical Engineering Industry Standards Committee. (c) BSI Electricity Council. 2 Heat treatment 1 2.5 Dimensions and tolerances 9 4.1 General inspection procedures 12 6 Purchasing information 6.3 Mechanical properties 1 2.5 Dimensions and finish 6 3. BS 4395-1:1969 Contents Page Co-operating organizations Inside front cover Foreword iii 1 General 1. Bechtel Ltd.4 General test requirements 6 3.6 Finish 9 4.3 Mechanical properties 6 Licensed Copy: Akin Koksal.4 General test requirements 9 4. Uncontrolled Copy. facing and marking of bolts 3 Figure 2 — Hexagon bolts 5 Figure 3 — Marking of nuts 7 Figure 4 — Hexagon nut 8 Figure 5 — Flat round washer 10 Figure 6 — Square taper washers 11 Figure 7 — Test piece 14 Figure 8 — Application of proof load to full size bolt 15 © BSI 03-1999 i .4 Test programme 1 2. 09 December 2002.1 Information to be supplied with enquiry or order 12 Appendix A BSI policy statement on screw threads and the metric system 13 Appendix B Testing of mechanical properties of steel bolts 13 Appendix C Testing of mechanical properties of steel nuts 16 Appendix D Test programme 18 Appendix E Recommended gauge for checking squareness of thread to face of nut 18 Appendix F Standard nominal lengths and preferred sizes of ISO metric high strength friction grip bolts (general grade) 19 Figure 1 — Chamfering.2 Heat treatment 6 3.7 Marking 9 5 Inspection 5.2 Terminology 1 2 Bolts 2.5 General test requirements 1 2.7 Marking 2 3 Nuts 3.1 Material 9 4. (c) BSI 3.2 Heat treatment 9 4.1 Material 6 3.1 Material 1 2.6 Marking 6 4 Washers 4.3 Hardness tests 9 4.6 Dimensions and finish 1 2.1 Scope 1 1. 09 December 2002. Uncontrolled Copy. Bechtel Ltd. (c) BSI ii © BSI 03-1999 . BS 4395-1:1969 Page Figure 9 — Wedge loading of full size bolt 16 Figure 10 — Proof load test for nut 17 Figure 11 — Nut squareness gauge 19 Table 1 — Number of pieces comprising a batch of bolts 1 Table 2 — Tolerance on nominal length 2 Table 3 — Thread lengths 2 Table 4 — Mechanical properties of bolts 4 Table 5 — Dimensions of hexagon head bolts 5 Table 6 — Number of pieces comprising a batch of nuts 6 Table 7 — Proof loads for nuts (coarse pitch series) 7 Table 8 — Dimensions of hexagon nuts 8 Table 9 — Number of pieces comprising a batch of washers 9 Table 10 — Dimensions of flat round washers 10 Table 11 — Dimensions of square taper washers 11 Table 12 — Dimensions for wedge loading test 16 Licensed Copy: Akin Koksal. Thread data and standard thread series. and requests received from industry for the provision of a specification for high strength friction grip bolts to basic metric dimensions. Testing of metals. BS 1580. dealt recommendations or draft proposals relating specifically to high strength friction grip bolts. BS 1916. account has been taken of current documentation prepared by ISO Committee ISO/TC 2 “Bolts. General grade metric series. thicknesses of nuts”. © BSI 03-1999 iii . Method for Vickers hardness test.000. ISO Draft Recommendation DR 987. This British Standard has been prepared under the authority of the Mechanical Engineering Industry Standards Committee as a result of the decision taken to adopt the ISO metric screw thread system in the United Kingdom (see Appendix A). “Bolts and screws. This standard makes reference to the following British Standards: BS 18. Although at present there are no ISO Recommendations. thread lengths for general purpose bolts”. will be found in the BSI Catalogue which may be purchased from BSI Sales Department. Uncontrolled Copy. ISO Draft Recommendation DR 952. BS 4395-1:1969 Foreword A complete list of British Standards. 1) In course of preparation. “Hexagon bolts and nuts. BS 3643-1. Limits and tolerances for coarse pitch series threads. as shown in the normal metric series. The Catalogue may be consulted in many public libraries and similar institutions. BS 427-1. BS 240-1. Limits and fits for engineering. Pipe threads. heights of heads. “Nominal lengths for bolts. widths across flats.. Testing of metals. have been selected in order to provide greater bearing areas for both bolts and nuts. (c) BSI BS 3643-2. BS 891-1. BS 3643. tolerances on widths across flats. radii under the head of general purpose bolts and screws. Methods for tensile testing of metals.. ISO Draft Recommendation DR 950. metric series. Although the basic hexagon sizes for the bolts and nuts are in accordance with ISO Recommendation R 272. numbering over 9. screws and studs. 09 December 2002. widths across corners”. metric series. Licensed Copy: Akin Koksal. BS 240. BS 21. BS. Testing of metals. “Hexagon bolts and nuts. The use of high strength friction grip bolts in structural engineering. BS 891.1). BS 427. Bechtel Ltd. Method for Rockwell hardness test. nuts and accessories”. Unified screw threads. the next larger width across flats for any given diameter. Method for Brinell hardness test. BS-1. fully indexed and with a note of the contents of each. metric series”. ISO metric screw threads. and where possible the provisions of the following ISO Recommendation and draft recommendations have been incorporated in the text of this standard: ISO Recommendation R 272.. 3) ASTM A 325. The thicknesses for the flat washers have been based on those currently given in BS 31392). Part 1. which in practice leads to a reduction in the tensile strength over the diameter range. 4) ISO Draft Recommendation No. 5) BS 3692. it was felt desirable to specify a maximum transition diameter consistent with their specialized function. 9114) and BS 36925) and the American practice as detailed in ASTM A 325. and the American Standard ASTM A 3253). since ISO is currently considering the adoption of structural steel sections covered by BS 4. The dimensions of square taper washers given in this standard have been based on the inch sizes at present given in BS 3139. whereas it is the American practice to maintain a generally constant chemical composition. “Additional tables for SI conversions”. as detailed in ISO Draft Recommendation No. NOTE 2 Although the mechanical requirements specified in this standard are in metric technical units (i. 1 kgf = 9. an alloy steel rather than a carbon steel would need to be used for diameters greater than 24 mm. It is continental practice to maintain a constant tensile strength Licensed Copy: Akin Koksal. “Mechanical properties of fasteners”. For further information about SI units see PD 5686. since it was felt that these thicknesses were more compatible with the function for which these washers are used. “ISO metric precision hexagon bolts. including the suitable nuts and plain hardened washers”.806 65 newtons. the washer thicknesses quoted in ISO/DR 940 being more applicable to ordinary hexagon bolts and nuts. This minor deviation was justified by the committee on the grounds that these products were not general purpose bolts and as such. kgf/mm2) in accordance with present ISO agreements (ISO/DR 911). iv © BSI 03-1999 . the transition diameter (da max. NOTE 1 Although the minimum radii under the head specified for bolts in this standard are in accordance with ISO/DR 987. Accordingly this Part 1 has been prepared with the material requirements based on the American Grade 5 material used in ASTM A 325 and BS 3139-1 (see notes to Table 1).8 for general grade metric high strength friction grip bolts to Part 1 of this standard. “High-strength carbon steel bolts for structural joints. and Supplement No. It also seems unlikely that a metric version of BS 4 would in any way change the flange angles. “Bolts. 09 December 2002. 911. It was originally intended to specify ISO strength Grade 8. 2) BS 3139. “High strength friction grip bolts for structural engineering”. On the question of the material to be utilized for general grade bolts to Part 1 of this standard.) quoted in Table 5 falls between the values quoted for finished and semi-finished products in the draft recommendation. comparable SI units have been included in anticipation of future international agreement in this respect. However. since it seems unlikely that BS 4 “Structural steel sections”. Bechtel Ltd. It was felt by the committee that economic considerations were important in this respect and might prove paramount for users intending to change over to metric products.8 was specified in Part 1. and there appears to be justification for retaining them as at present. the BSI committee responsible were unable to reconcile the different practices adopted on the continent. screws and studs”.e. screws and nuts”. Part 1.9 for high grade bolts in the envisaged Part 2 (see BS 3692). it was pointed out in committee that if ISO strength Grade 8. BS 4395-1:1969 The diametral dimension for the flat washers given in this standard have been based on the “large diameter series” detailed in draft ISO Recommendation No. 940 “Washers for hexagon bolts — metric series”. “General grade bolts”. (c) BSI throughout the diameter range of threaded products. 1 (1967) to BS 350-2. and ISO strength Grade 10. Uncontrolled Copy. “The use of SI units”. thus necessitating a change in chemical composition because of the increase in ruling section. will be revised to provide rational metric sizes for sections in the near future. Licensed Copy: Akin Koksal. pages i to vi. Compliance with a British Standard does not of itself confer immunity from legal obligations. Uncontrolled Copy. Users of British Standards are responsible for their correct application. This will be indicated in the amendment table on the inside front cover. This standard has been updated (see copyright date) and may have had amendments incorporated. pages 1 to 19 and a back cover. an inside front cover. (c) BSI Summary of pages This document comprises a front cover. Bechtel Ltd. © BSI 03-1999 v . 09 December 2002. BS 4395-1:1969 A British Standard does not purport to include all the necessary provisions of a contract. Licensed Copy: Akin Koksal. 09 December 2002. Bechtel Ltd. (c) BSI vi blank . Uncontrolled Copy. A batch shall consist of the number of Any alternative method of use should be left to the responsibility pieces shown in Table 1.6.6. (Figure 2). Should any specimen fail to meet the plies of connected members. mechanical properties are specified.2 Retests. 09 December 2002. used in conjunction including 16 mm thereof with high tensile steel nuts and quenched and Over 16 mm up to and 5 000 or fraction thereof tempered steel washers.5.1.6. inspection procedure and provisions for stated in the enquiry. which are tightened to a including 24 mm predetermined shank tension in order that the clamping force thus provided will transfer loads in Over 24 mm 2 500 or fraction thereof the connected members by friction between the parts and not by shear in or bearing on the bolts or 2. or both. Bechtel Ltd.. 6) This term includes both top and bottom blown oxygen processes. marking are also included.1 Scope The manner in which tests are to be carried out is specified in Appendix B. The tests indicated by the symbol “_” may be from 12 mm (M 12) to 36 mm (M 36) inclusive and carried out at the special request of the purchaser. NOTE Attention is drawn to the importance of ensuring that these bolts are correctly used if satisfactory results are to be 2.6.5. together with preferred 2. Part 1 of this British Standard specifies requirements for one (general) grade of quenched 2. including any oil or water and shall then be tempered..008 %.1 Material requirements of the test the batch shall be deemed to comply with this standard. Bolts shall meet the requirements set out in Table 4 2. 2. batch of bolts.2 Tolerance. “The use of high strength friction grip bolts in structural engineering”.3 Mechanical properties size combinations of diameter and length. In the case of the oxygen processes the bolts shall be in accordance with the requirements maximum content of nitrogen shall not specified in 2.. Steel used in the manufacture shall be that produced by the open-hearth.4). © BSI 03-1999 1 .5 General test requirements obtained.2 Heat treatment 2. of the engineer and should be noted on the appropriate drawings Table 1 — Number of pieces comprising a Licensed Copy: Akin Koksal. order or contract. “General Appendix D shall be carried out three times per grade metric series” (in course of preparation). Recommendations giving guidance in the use of this 2.1 Number of tests.1 to 2. Full details of If these tests are required. BS 4395-1:1969 1 General NOTE The figures given in Columns 4 to 10 inclusive of Table 4 are minimum values. The tolerance on the nominal for all properties selected for the test programme length shall be as given in Table 2.7 inclusive and in Table 5 exceed 0. an additional sample of double the number of specimens from the 2 Bolts same batch at the time of manufacture shall be tested and if all the additional specimens satisfy the 2.06 % The dimensions. Uncontrolled Copy. (see 2. The nominal length of the Bolts shall be heat-treated under uniform bolt shall be the distance from the underside of the conditions. properties for bolts and indicates by the symbol “¤” the tests to be carried out by the supplier for all Dimensions are given for a range of nominal sizes bolts. chamfer or radius.1 Nominal length. The maximum content of sulphur and phosphorus shall not exceed 0.1. 1. The standard nominal lengths are given in Appendix F.2 Terminology Diameter of bolt d Number of pieces in batch The term “high strength friction grip bolts” relates Up to and 15 000 or fraction to bolts of high tensile steel.1 Length of bolts 2.6 Dimensions and finish oxygen processes6).. requirements of a specified test.4 Test programme and tempered high strength friction grip hexagon head bolts and their associated nuts and washers for Appendix D consists of a list of mechanical use in structural engineering. Each test selected from form of fastener are given in BS . They shall be hardened by quenching in head to the extreme end of the shank. electric or any of the 2. Part 1. tolerances and general finish of the each. batch of bolts 1. (c) BSI or documents. this should be clearly tests. Table 5 and subject to a tolerance of plus 0.6.6.00 smaller than 90 % of the minimum across-flats 180 250 ± 2.6 Diameter of shank.4 Length of thread.5 times the pitch of the thread. “Thread data and standard thread series”.3 Screw threads Column 2.6.7 Marking bolts shall be the distance from the end of the bolt Bolts shall be identified as general grade high (including any chamfer or radius) to the leading face strength friction grip bolts by being marked with of a screw ring gauge which has been screwed as far three radial lines 120° apart. 2. fillet radius in the bore equal to the maximum 2. 2 © BSI 03-1999 .2 Tolerances. 250 315 ± 2.6. ISO metric thread (see Figure 1). The ends of bolts may. “Limits and tolerances for coarse pitch series threads”.85 equal to that produced by machining. the manufacturer’s identification mark and in The length of thread run out shall not addition shall be marked “ISOM” or “M” to signify exceed 2. The maximum and 2. 400 500 ± 3.2 Ends of bolts. including providing the radius specified in Table 5 is mm mm mm maintained. (c) BSI equal to 1Ô times the nominal diameter of the ring gauge having an internal diameter equal to the shank. Uncontrolled Copy. Table 3 — Thread lengths Nominal length of bolt Length of threada Up to and 2d + 6 mm including 125 mm Over 125 mm up to and including 200 mm 2d + 12 mm Over 200 mm 2d + 25 mm ad = thread diameter (see Table 4). The standard thread lengths are based on the formulae set out in Table 3.3. BS 4395-1:1969 Table 2 — Tolerance on nominal length 2. The diameter of the ring formed by the chamfer on the upper face of the bolt shall not be 120 180 ± 2. The depth of the thread or with a radius approximately shank diameter shall be capable of acceptance by a Licensed Copy: Akin Koksal. a minimum with BS 3643-17). and diameters A suitable design of gauge for this test would be a and associated pitches of general grade metric high plain ring gauge having a maximum thickness equal strength friction grip bolts shall be in accordance to the nominal diameter of the bolt. They shall also bear as possible on to the bolt by hand.6.1 General.6. The bearing face shall be machined or have a surface 315 400 ± 2. Tolerance on Bolts that are too short for minimum thread length Over Up to and length shall be threaded as near to the head as possible. Bechtel Ltd. Columns 2 and 3.025 mm to plus 0. maximum shank diameter as specified in 2. Part 1. 09 December 2002. The form of thread.50 chamfered at an angle of approximately 30° on their 80 120 ± 1. Part 2. 30 50 ± 1.5 Chamfering and facing.6. The screw threads shall be made radius under the bolt head and an internal diameter to the tolerances for the “medium” class of fit (6 g) as as specified above. 7) BS 3643. 2.30 dimension (see Figure 1). The heads shall be 50 80 ± 1.4.050 mm. at the minimum diameters of the unthreaded portion of option of the manufacturer.15 2. be finished with either the shank of the bolt shall be in accordance with a 45° chamfer to a depth slightly exceeding the dimensions given in Table 5. “ISO metric screw threads”.3. The tolerances on bolt thread Nominal length lengths shall be plus two pitches for all diameters.60 The lower or bearing face shall be washer-faced.75 upper faces. The length of thread on 2.6.25 2.1 Tolerances. specified in BS 3643-27). Licensed Copy: Akin Koksal. facing and marking of bolts 3 BS 4395-1:1969 . Bechtel Ltd. (c) BSI © BSI 03-1999 Figure 1 — Chamfering. Uncontrolled Copy. 09 December 2002. 04 kgf/mm2 (512 N/mm2) for sizes M 27 to M 36 inclusive.2 min.7 kgf/mm2 (635 N/mm2) for sizes M 12 to M 24 inclusive and 56.51 418 12 295 223 30 19 292 225 NOTE 1 The tensile stress area is calculated from the following formula: Ï Ï A s = --.7 9. do not warrant the usage of a larger size bolt than M 12.64 144 12 321 255 34 25 330 260 M 22 2. mm mm mm2 M 12a 1. (1 000 kgf) (1 000 kgf) (1 000 kgf) min. Table 4 — Mechanical properties of bolts 4 BS 4395-1:1969 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Pitch Tensile Hardness (see Note 5) Nominal of Yield load or load Elongation size and thread stress Ultimate load (see Note 2) permanent set at limit Proof load thread (coarse area (see min.5 5. (c) BSI d p As tonne-force tonne-force tonne-force percent kilo-newtons kilo-newtons kilo-newtons Max.57 250 19. such as material thickness.45 53.35 445 42.73 kgf/mm2 (558 N/mm2) for sizes M 27 to M 36 inclusive.6 5. NOTE 3 Based on 64.2 min (see Note 4) min.32 591 46.71 203 15. © BSI 03-1999 .0 459 33. 2) yield load (or load at permanent set limit R0. after Rockwell Vickers diameter pitch fracture Brinell HB (see Note 3) min.4 12 321 255 34 25 330 260 M 16 2. Only to be used for the lighter type of construction where practical conditions.5 561 41.(mean of effective and minor diameters)2 = ----.04 49.38 kgf/mm2 (827 N/mm2) for sizes M 12 to M 24 inclusive and 73.10 207 12 321 255 34 25 330 260 M 27 3.0 817 60. Max. R0. Bechtel Ltd.82 313 29.85 155 14.0 353 29. a Non-preferred.(effective diameter + minor diameter)2 4 16 NOTE 2 Based on 84.2 min). Min.3 7. Min.77 kgf/mm2 (587 N/mm2) for sizes M 12 to M 24 inclusive and 52.42 406 31. 09 December 2002.04 259 23.25 130 10.16 99.1 12 321 255 34 25 330 260 M 20 2.79 292 22.39 92. Max. 3) hardness tests. Equivalent to stress at permanent set limit R0.89 333 26. NOTE 6 See Appendix B for method of carrying out: 1) ultimate load test. proof load and elongation tests.1 69.75 84.5 303 25.19 286 12 295 223 30 19 292 225 M 36 4.88 234 12 295 223 30 19 292 225 M 30 3.83 kgf/mm2 (725 N/mm2) for sizes M 27 to M 36 inclusive. NOTE 4 Based on 59.94 225 21.60 192 18. NOTE 5 Hardness values are given for guidance only. Uncontrolled Copy. HRC HV 30 series) Note 1) Licensed Copy: Akin Koksal.1 177 12 321 255 34 25 330 260 M 24 3.0 157 13. Min.5 245 20. 0 37.90 13.1 50.5 20.00 36.24 14.2 29.05 21.8 25.75 0.0 35.75 12.00 0.84 26.00 53.90 16. Min.16 46 45.16 50 49.5 30.4 1. series) M 12a 1.20 41 38. Uncontrolled Copy. Min.95 M 36 4.7 8.0 27.84 21.05 17.5 1.10 M 27 3.30 27 24.84 17.16 31.00 57. Table 5 — Dimensions of hexagon head bolts © BSI 03-1999 Licensed Copy: Akin Koksal. 09 December 2002.6 14.90 14.24 15.5 1.4 23.3 45. Max.37 50 47.0 30.8 23. Max.10 M 24 3. Max.00 41.0 24.95 a Non-preferred.7 55.5 1.70 22 19. Only to be used for the lighter type of construction where practical conditions.30 22 21.6 39.3 66.55 36 33.0 40. 5 .00 24.84 19.30 27 26.0 16.45 9. Max.75 0.84 20.4 1.9 35.2 0. Min.8 27.6 18.10 BS 4395-1:1969 M 30 3.45 7.00 47.75 0. Max. Max.16 32 31.03 32 29.91 0.00 0.2 0.10 M 22 2.5 1.24 13.55 M 20 2.70 11. Min.16 25.91 0.5 1.84 29.2 0.4 1. do not warrant the usage of a larger size bolt than M 12.5 1. Min.75 0.85 46 43.90 12.0 33. such as material thickness.5 1.44 60 57.16 36 35.84 23. (c) BSI Figure 2 — Hexagon bolts Dimensions in millimetres 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Diameter of Depth Pitch of Width across Diameter of of Radius under Transition Thickness of unthreaded Width across flats washer thread shank corners washer face head diameter head Nominal face size and thread df diameter p d s e c r da k d (coarse pitch Max.55 M 16 2.80 69. Min.0 60 58.16 41 40.7 10.70 15.5 22. Bechtel Ltd.4 1. Max.75 0.75 0. 3 Squareness of threads to face.1. Max. electric furnace.5. (c) BSI hardness shall not be outside the following ranges.2 Retests.4 General test requirements A gauge recommended for carrying out this test together with the manner in which the test is to be 3.5. Bechtel Ltd. an additional sample of double the number of specimens from the same batch at the time of manufacture shall be tested and if all the additional specimens satisfy the requirements of the test the batch shall be deemed to comply with this standard. Nuts for use with standard grade high strength friction grip bolts shall be identified by being Table 6 — Number of pieces comprising a marked on the chamfered face with three similar batch of nuts circumferential arcs 120 degrees apart.5.1 Material nuts shall be in accordance with the requirements Steel used in the manufacture of nuts shall be that specified in 3.5. Uncontrolled Copy. Licensed Copy: Akin Koksal.1. Free cutting 3.5 Dimensions and finish The dimensions. oxygen or acid Bessemer processes. 09 December 2002.1 Screw threads steel shall not be used. They shall Diameter of nut Number of pieces in batch also be marked with the letter “M” (see Figure 3).6 Marking A batch shall consist of the number of pieces shown in Table 6.1 to 3.3.2 Chamfering and facing.2 Tolerances.2 Heat treatment and associated pitches for general grade metric high strength nuts shall be in accordance with Nuts shall be heat-treated under uniform BS 3643-18). Brinell HB 166 HB 302 3. The screw threads shall be made oil and shall then be tempered. tolerances and general finish of the 3. chamfered at an angle of approximately 30° on their 3. Part 2. If nuts of 30 mm upper faces and they shall have a washer face on the diameter or over cannot be subjected to the proof bearing surface.1 Hardness test on nuts. they the chamfer on the nut shall not be smaller shall be subject to a hardness test and their than 90 % of the minimum across-flats dimension.1 Number of tests. The bearing surface of the nut shall be machined or Min. 3.1 General. 8) BS 3643. “Thread data and standard thread series”. 6 © BSI 03-1999 . “ISO metric screw threads”.4. as appropriate. due to lack of suitable equipment.4. BS 4395-1:1969 3 Nuts 3. They shall be hardened by quenching in 3. conditions. who may also use additional marking for his own purposes. for the proof load or hardness test. Part 1. The form of thread and diameters 3. Table 8.5.5.3 Mechanical properties 3. The bearing surface of the nut shall be square to the axis of the Rockwell HRB 88 HRC 30 thread of the nut within the tolerances given in Vickers HV 175 HV 310 Column 11. Nuts shall be Nuts shall meet the requirements set out in Table 7. from each batch of nuts at the time of manufacture. 3. Three nuts shall be selected undertaken is shown in Appendix E. 3. 3. The diameter of the ring formed by load test. Should any specimen fail to meet the requirements of a specified test. to the tolerances for medium class of fit (6H) as specified in BS 3643-28).6 inclusive and in Table 8 produced by the open-hearth. Over 16 mm up to and 5 000 or fraction thereof including 24 mm Over 24 mm 2 500 or fraction thereof 3. (Figure 4). have a surface equal to that produced by machining. “Limit sand tolerances for coarse pitch series threads”. Up to and 15 000 or fraction Markings may be either embossed or indented at including 16 mm thereof the option of the manufacturer. 6 84. Uncontrolled Copy. © BSI 03-1999 7 . Bechtel Ltd. see Appendix C.0 245 M 22 30. BS 4395-1:1969 Figure 3 — Marking of nuts Table 7 — Proof loads for nuts (coarse Licensed Copy: Akin Koksal. NOTE 2 For method of carrying out test.0 157 M 20 25.2 561 M 36 83.3 M 16 16.3 817 NOTE 1 Based on 102 kgf/mm2 (1 000 N/mm2) on the equivalent stress area of the corresponding bolt (see Table 4).0 353 M 27 46. 09 December 2002. (c) BSI pitch series) 1 2 3 Nominal size and Proof load thread diameter d tonne-force kilo-newtons (1 000 kgf) M 12 8.8 459 M 30 57.9 303 M 24 36. 46 M 20 2.00 58. (c) BSI Figure 4 — Hexagon nut Dimensions in millimetres 1 2 3 4 5 6 7 8 9 10 11 12 Depth of Tolerance Pitch of Width across flats Width across corners Diameter of washer washer Thickness of nut on thread Nominal size face squareness and thread (see 3.00 53.75 0.00 29.5 24.75 0. Max.20 29.5 36.00 41.5 22.00 33.82 22.00 31.75 0.00 45.00 57. 09 December 2002.45 0. Max.4 15.45 0. Table 8 — Dimensions of hexagon nuts 8 BS 4395-1:1969 Licensed Copy: Akin Koksal.35 0.00 49.0 60.03 32.4 19. .5. Max.85 46.00 35.00 36. Max.78 © BSI 03-1999 M 30 3.0 27.70 55.00 47.20 1.80 30.90 35.30 27.75 0.00 47.4 11. Only to be used for the lighter type of construction where practical conditions such as material thickness do not warrant the usage of a larger size bolt than M 12.45 0.85 M 36 4.00 26.30 45.54 M 22 2.55 10.65 23.40 23.55 14.00 57.5 50.00 19.35 0.44 60.55 36. Min.16 25.75 22.55 17. Max.00 40. series) M 12a 1.00 24.65 18.35 0.91 0.0 41.70 M 27 3.00 21.75 0.00 43.16 31.91 0.03 a Non-preferred. Min.5 32.65 25.61 M 24 3.3) p s e df c m diameter d (coarse pitch Max.35 0. Min.5 26.37 M 16 2.75 0.30 66.0 46. Min.5 31.00 38. Uncontrolled Copy.65 21.4 18. Bechtel Ltd.60 39.80 69.37 50.20 41.10 50. 3 Clipped washers.3 Hardness tests necessary. electric furnace. plain washers may be clipped on one side 4. 5° and 8° 4.6 Finish 4. 5° and 8° taper washers shall have a hardness of 362 to 440 HV 30.5 Dimensions and tolerances 4.2 Taper washers. angles are required. the preparation of test specimens and the method of The surfaces of the washers shall be flat and smooth.4. 10) BS 427. 9) BS 891. Tapered washers shall be 4.7. “Method for Rockwell hardness test”.4 General test requirements of taper indicated by the following features: 4.7 Marking Licensed Copy: Akin Koksal.3.4. 5° taper washers shall be chamfered on one Table 9 — Number of pieces comprising a corner as shown in Figure 6b. with high strength friction grip bolts shall be 4. Scale 38 to 45 HRC. Standard angles of taper are 3°. In this case indented letter “M” as shown in Figure 5.1 Material washers shall be in accordance with Table 10 Steel used in the manufacture of washers shall be (Figure 5). BS 4395-1:1969 4 Washers 4. up to and 15 000 or fraction including 16 mm thereof over 16 mm up to and 5 000 or fraction thereof including 24 mm over 24 mm 2 500 or fraction thereof 4. Flat round washers for use specified in BS 891. a load of 30 kg shall be applied and the washers 4. 3°.2 Heat treatment and the purchaser shall specify which of these Washers shall be quenched and tempered.3.1 Plain washers. taper washers shall be in accordance with Table 11 (Figure 6). testing shall be in accordance with BS 8919) and the hardness values shall be determined in accordance with Rockwell C scale. © BSI 03-1999 9 .5. Uncontrolled Copy. When clearance makes it 4. Should any specimen fail to meet the requirements of a specified test. (c) BSI tested on the sheared edge to obtain a flat surface as 4. The dimensions of square oxygen or acid Bessemer process.3.3 Alternatively the Diamond Pyramid method in identified by the provision of three nibs and an accordance with BS 42710) may be used. 4.7.2 Taper washers. 09 December 2002. that produced by the open-hearth. The dimensions of plain 4. Rockwell C. “Method for Vickers hardness test”.2 Retests. at a point not closer than seven-eighths of the bolt The hardness shall be as follows: diameter from the centre of the washer. Bechtel Ltd. 4. an additional sample of double the number of specimens from the same batch at the time of manufacture shall be tested and if all the additional specimens satisfy the requirements of the test the batch shall be deemed to comply with this standard.5. A batch shall rounded to avoid sharp edges.2 When the Rockwell method is used.1 Number of tests.1 Plain washers. batch of washers 8° taper washers shall be chamfered on two Washers for bolt sizes Number of pieces in batch corners as shown in Figure 6c.5.1 Washers shall be subjected to a hardness test. Three washers shall be 3° taper washers shall have a projection as selected for the hardness test from each batch of shown in Figure 6a. This projection shall be washers at the time of manufacture. consist of the number of pieces shown in Table 9. 4. for use with high strength friction grip bolts shall be identified with an indented letter “M” and the angle 4. Max.4 66 64. BS 4395-1:1969 Table 10 — Dimensions of flat round washers Figure 5 — Flat round washer Dimensions in millimetres 1 2 3 4 5 6 7 Nominal size and thread Inside diameter B Outside diameter C Thickness A Licensed Copy: Akin Koksal.3 M 22 23.5 21. M 12a 13.4 26. 09 December 2002. Bechtel Ltd.8 2.4 85 83.8 38.5 4.8 M 36 38.4 3. Min. Max.8 M 30 32.4 29.2 3.5 4.0 M 20 21.5 4.4 30 29 2.8 32.2 a Non-preferred 10 © BSI 03-1999 . Min.4 M 16 17.1 44 43 3. Uncontrolled Copy.5 4.7 3.0 56 54.5 4. Min.2 3.0 60 58.2 3.2 3. (c) BSI diameter d Max.0 50 48.8 17.6 4.8 M 27 29.8 13.8 M 24 26.4 37 36 3.4 23. 35 M 30 33.35 M 36 39.75 4.0 57.76 6.0 57.15 4.2 32. BS 4395-1:1969 Table 11 — Dimensions of square taper washers Licensed Copy: Akin Koksal.15 4.76 6.4 57.4 57.4 31.76 6. 3° and 5° Taper 8° Taper M 12 a 14.8 29.35 M 24 26.76 6.0 44.2 38.8 23.2 13.8 26.76 6.35 M 27 29.76 6. (c) BSI Figure 6 — Square taper washers 1 2 3 4 5 6 Nominal size and thread Inside diameter B Mean thickness A diameter Overall size C Max.2 17.35 M 20 21.10 4.76 6. Min.10 4.35 M 16 18.15 4.45 4.76 6.1 38. 09 December 2002.4 38.9 21. Uncontrolled Copy.35 a Non-preferred © BSI 03-1999 11 . Bechtel Ltd.35 M 22 23.15 4. : reasonable times while work on the contract of the “Nuts M 20 to BS 4395-1”.1. purchaser is being performed. e. to satisfy him that the material is being furnished in accordance Licensed Copy: Akin Koksal. (c) BSI with the requirements of this standard. Such inspection length of bolt in millimetres shall also be given.1. 5.g.1 Information to be supplied with 5.g. For washers the nominal diameter manufacturer’s works concerned with the and type of washer (e.3 Washers. 09 December 2002. The manufacturer shall take the enquiry or order necessary steps to ensure that the conditions In all cases when making enquiries or orders for relating to dimensions and tests laid down in this products in accordance with this standard the standard are fulfilled. to all parts of the 6. all tests and inspection shall be carried out at the place of manufacture prior to the despatch of the finished material from the works and shall be so conducted as not to interfere unnecessarily with the operation of the works.1.1 General inspection procedures 6. Bechtel Ltd. “Bolts M 20 × 120 to BS 4395-1”.: manufacturer shall afford the inspector all “Washers M 20 × 5° taper to BS 4395-1”. the purchaser standard number shall be given (i. desires to make his own inspection. without charge.1. e. he shall state so 6.g.1 General.e. The or 8°) shall also be given. 5° manufacture of the material ordered.2 Purchaser’s inspection. BS 4395-1:1969 5 Inspection 6 Purchasing information 5. The inspector 6. Uncontrolled Copy. flat round or taper 3°. Unless otherwise specified.g. BS 4395-1). at all the nominal diameter and standard number. reasonable facilities.1.: shall be carried out in accordance with the terms stated in 5. 12 © BSI 03-1999 .1 Bolts. If. For nuts it is only necessary to specify representing the purchaser shall have access. e.1.2 Nuts. For bolts the nominal diameter and in his enquiry and contract or order. in addition.2. 11) BS 3643. with maximum efficiency and economy of When machining the test specimen the reduction of production lies behind the above statement and the shank diameter of heat-treated bolts makes it essential to give urgent and serious over 16 mm thread diameter shall not exceed 25 % consideration to the screw thread situation in the of the original diameter (about 44 % of the United Kingdom. 13) BS 18. 1965 the Right Hon. after approximately 0. Prior to the conference the statement had been NOTE Threads on pipes will continue to be BSP (to BS 21 “Pipe endorsed by the Mechanical Engineering Industry threads”) which have been adopted as the ISO pipe thread and Standards Committee. Part 1. 1965. Part 1.3 Rockwell hardness test. “Unified screw threads”. should adopt metric units sector by sector. industry will have effected the change . 15) BS 891. and having particular regard to the declared UK national policy for its adoption.2 %. to continue with their use for some make the internationally agreed ISO metric thread their first choice (with the ISO Unified thread as time. announced in properties of steel bolts (See 2. “Methods for tensile testing of metals”.. © BSI 03-1999 13 ..4 mm has been removed by grinding.. “Testing of metals”. (c) BSI country to change to the metric system. 12) BS 1580. after screw threads and to minimize the present approximately 0. superseded by ISO metric threads in preference to an intermediate change to ISO inch threads. the ball or cone shall be applied either on the top of the head or to the centre position of the end of the bolt. on 23rd November. Bechtel Ltd. gauge ten years the greater part of the country’s length 5.3) Parliament that it would be desirable for this B. the Government hope that within 3) Percentage elongation after fracture. Licensed Copy: Akin Koksal. (Unified) screw threads may find it necessary.2 Brinell hardness test.4 mm has been removed by diversities of practice. Whitworth and BA threads should be second choice) for all future designs. until that system can become in time the primary 2) Yield stress or stress at permanent set limit system of weights and measures for the country of 0. “ISO metric screw threads”. BS 4395-1:1969 Appendix A BSI policy statement on In view of the world trend towards the metric screw threads and the metric system system. the Engineering Divisional which are covered in ISO Recommendation R7. as a whole . “Pipe threads for Council and the General Council of BSI. British industries on a broadening front 1) Tensile strength. gas list tubes and screwed fittings where pressure-tight joints are made on the threads (° in to 6 in)”. After many years’ work the International B.” Machine the test piece as illustrated in Figure 7 The national need for increased exports coupled from an actual bolt or bolt blank. The ISO Recommendations comprise a system of B. Douglas Jay. “Method for Rockwell hardness test”. This agreement will enable be applied either on the top of the head or to the the industries of the world to align the usage of centre position of the end of the bolt. BA and BSF. “Testing of metals”. The impression of the existing Unified threads.. the Appendix B Testing of mechanical President of the Board of Trade. and to various reasons.65 Æarea. for Whitworth. “Method for Brinell hardness test”. it is The major sectors of British industry were strongly recommended that British industry should represented at a conference organized by the BSI adopt the ISO metric screw thread system. The Rockwell ISO metric threads11) and a system of ISO inch hardness test shall be performed in accordance with threads12)... An extract Perform the tests in accordance with the from his statement is given below: requirements of BS 1813) to determine the following: “. as obsolescent. Uncontrolled Copy. The ISO inch threads are the same as the requirements of BS 891-115). The impression should purpose screw threads. grinding.. 09 December 2002. The Brinell hardness Organization for Standardization (ISO) has reached test shall be performed in accordance with the agreement on ISO Recommendations for general requirements of BS 240-114). cross-sectional area) of the test specimen. They gave their approval Although it is appreciated that some of those to a policy statement which urged British firms to sections of industry already using ISO inch regard the traditional screw thread systems.1 Tensile testing of machined test pieces. 14) BS 240. The following is the text of the policy statement: On 24th May. Bechtel Ltd.5 micrometres. BS 4395-1:1969 Licensed Copy: Akin Koksal.4 Vickers hardness test. The extension of the bolt shall be measured. with a suitable instrument. Figure 7 — Test piece B. “Testing of metals”. The Vickers hardness B. (c) BSI NOTE The head of the test piece may be manufactured either with or without the original washer face of the bolt. 16) BS 427. The instrument shall be such that the total of inaccuracies due to measurement does not exceed ± 5 micrometres. machine (see Figure 8).5 Proof load testing for full size bolts. “Method for Vickers hardness test”.4 mm has been removed by axially to the bolt in a normal tensile testing grinding. The test shall be performed in accordance with the proof load test consists of applying the proof load. The proof load is applied after approximately 0. extension of the bolt. 09 December 2002. after the proof load has been applied for not less than 10 seconds. Part 1. shows an extension of not more than 12. which is obtained from the indenter shall be applied either on the top of the proof stress and measuring any permanent head or to the centre position of the end of the bolt. at its true centre line. The length of free thread above the nut or adaptor (between nut or adaptor and head of bolt) shall be between half and one diameter. The impression of the specified in Table 1. requirements of BS 427-116). Uncontrolled Copy. The test is considered satisfactory if the measurement. 14 © BSI 03-1999 . diameter. 09 December 2002. If failure occurs due load (see Figure 9).2 To meet the requirements of this test it is full size bolts necessary for the fracture to occur in the shank or B. with a hardened wedge (in accordance This test is passed if the fracture originates in the with Table 12) placed under the head. Subject the bolt to an axial load to the stripping of the thread.6. occurs. until fracture substituted. Uncontrolled Copy. the individual test at a testing machine crosshead speed (free running) shall be discarded and another specimen not greater than 26 mm per minute.6. Position the threaded part even if the fracture extends into the bolt so that no corner of the hexagon takes bearing fillet or head before separation. BS 4395-1:1969 Licensed Copy: Akin Koksal.6 Test for strength under wedge loading for B. © BSI 03-1999 15 .1 Screw the bolt into a threaded adaptor or nut. thread and not between the head and the shank. (c) BSI Figure 8 — Application of proof load to full size bolt B. Bechtel Ltd. the distance from the thread runout of the bolt to The bolt should meet the minimum tensile strength the face of the nut or adaptor being one nominal given in Table 4 before fracture occurs. The thread shall be tolerance class 4 h except that the major C. (c) BSI Figure 9 — Wedge loading of full size bolt Table 12 — Dimensions for wedge loading test Nominal size and thread diameter Angle ! ± 30 r c For bolts with plain For bolts with plain Above Up to and including shank length 2d or shank length less above than 2d mm mm — 20 1. The mandrel shall have a properties of steel nuts (See 3.3 10° 6° 20 30 3. C.3 It may he necessary to use a manual wrench to start the nut in motion. C.3) hardness of not less than Rockwell C45.6 6° 4° Appendix C Testing of mechanical C. in Note 1 to Table 7. BS 4395-1:1969 Licensed Copy: Akin Koksal. 09 December 2002.1. C.1. Such wrenching is permissible providing it is restricted to a half turn and the nut is then removable by the fingers following initial loosening. If the threads of the mandrel are damaged during the test.6 1. the test shall be discarded.1. Uncontrolled Copy.2 1.1 Proof load test. Bechtel Ltd. and should be removable by the fingers after the load is released.2 The nut shall withstand this load without failure by stripping or rupture. The proof load test consists of diameter shall be equal to the minimum major applying the relevant proof load given in Table 7 diameter for class 4 h with a plus tolerance of one which was obtained from the proof load stress given quarter of the 6 g major diameter tolerance.1 Assemble the nut to be tested on a hardened and tempered mandrel as shown in Figure 10 and apply the specified load in an axial direction.2 Hardened mandrel. 16 © BSI 03-1999 . 17) BS 240. Part 1. “Method for Vickers hardness test”. Rockwell or C. © BSI 03-1999 17 . Uncontrolled Copy. “Testing of metals”. “Method for Brinell hardness test”.3 Hardness tests on nuts. 19) BS 427. Part 1.2 Perform a Rockwell hardness test in a hardness of not less than Rockwell C38. C. impression to the top or bottom face of the nut. “Testing of metals”. 18) BS 891.4. Bechtel Ltd. (c) BSI Figure 10 — Proof load test for nut C. “Method for Rockwell hardness test”.1 Perform a Brinell hardness test in accordance with the requirements of BS 240-117). accordance with the requirements of BS 891-118). 09 December 2002. otherwise on the side of the nut. Apply the with the requirements of BS 427-119). Part 1.3 Perform a Vickers hardness test in accordance Vickers hardness may be determined. Brinell.3 Hardened test plate.4. BS 4395-1:1969 Licensed Copy: Akin Koksal. “Testing of metals”. C.4. The test plate shall have C. Mechanical property Test method By arrangement between manufacturer and purchaser _ 1. With the sleeve in this position it shall not be possible for a feeler gauge of thickness equal to the squareness tolerance to enter anywhere between the leading face of the nut and the face of the sleeve. Yield stress or stress at Tensile test using test piece permanent set limit of 0. 09 December 2002.5. Percentage elongation after Tensile test using test piece fracture ¤ 4. Appendix E Recommended gauge for checking squareness of thread to face of nut (See 3. (c) BSI bolt NOTE If all tests are required. The face of the sleeve shall be brought into contact with the leading face of the nut. and each test is carried out once. Uncontrolled Copy. Strength under wedge Wedge loading test on bolt ¤ Bolts M 30 and under onlya loading 6.3) Figure 11 shows the recommended gauge for checking the squareness of the thread to the face of the nut. 18 © BSI 03-1999 . Hardness Rockwell or Vickers test on _ Licensed Copy: Akin Koksal. a Based on the availability of a 51 tonnes testing machine.2 % _ 3. The nut shall be screwed by hand onto the mandrel of the gauge until the thread of the nut is tight on the thread of the mandrel. Tensile strength Tensile test using test piece without wedge ¤ 2. BS 4395-1:1969 Appendix D Test programme Obligatory ¤ Test No. Stress under proof load Proof load test on bolt without wedge ¤ 5. two bolts are sufficient for this purpose. Bechtel Ltd. 19 . a Non-preferred. 09 December 2002. Bechtel Ltd. Uncontrolled Copy. The purchaser is requested to consult with the manufacturer concerning lists of stock production sizes. © BSI 03-1999 Licensed Copy: Akin Koksal. Only to be used for the lighter type of construction where practical conditions such as material thickness do not warrant the usage of a larger size bolt than M 12. (c) BSI Figure 11 — Nut squareness gauge Appendix F Standard nominal lengths and preferred sizes of ISO metric high strength friction grip bolts (general grade) Nominal Standard nominal lengths size and thread 40 45 50 55 60 65 70 75 80 85 90 100 110 120 130 140 150 160 170 180 190 200 220 240 260 280 300 325 350 375 400 425 450 475 500 diameter d M 12a X X X X X X X X X X X X X X X X X X X X X X X X X X X M 16 X X X X X X X X X X X X X X X X X X X X X X X X X M 20 X X X X X X X X X X X X X X X X X X X X X X X M 22 X X X X X X X X X X X X X X X X X X X X X X M 24 X X X X X X X X X X X X X X X X X X X X X M 27 X X X X X X X X X X X X X X X X X X X X X X X X X X X X M 30 X X X X X X X X X X X X X X X X X X X X X X X X X X BS 4395-1:1969 M 36 X X X X X X X X X X X X X X X X X X X X X X X X NOTE The inclusion of dimensional data in this standard is not intended to imply that all of the products described are stock production sizes. Tel: 020 8996 7111. Various | | BSI electronic information services are also available which give details on all its | | products and services. | | | | | | | | | BSI | | 389 Chiswick High Road | | London | | W4 4AL | | | | | | | . | | | Revisions | | | British Standards are updated by amendment or revision. international and foreign standards publications should be | | addressed to Customer Services. the terms may include royalty payments or a licensing | | agreement. | | | BSI offers members an individual updating service called PLUS which ensures that | | subscribers automatically receive the latest editions of standards. | | the identity of which can be found on the inside front cover. | | | If permission is granted. | | | | | | | | | BSI Ð British Standards Institution | | | | | | | BSI is the independent national body responsible for preparing British Standards. type or grade designations. 09 December 2002. | | | Information on standards | | BSI provides a wide range of information on national. in the course of implementing the standard. | | Fax: 020 8996 7400. | | Tel: 020 8996 7070. it is BSI policy to supply the BSI | Licensed Copy: Akin Koksal. | | | Buying standards | | Orders for all BSI. | | | In response to orders for international standards. 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