BRITIS H S TAND ARD BS AU -2 : 994 Tyres and wheels — Part : Wheels and rims — Section : Sp ecification for road-wheel nuts, studs, and b olts for commercial vehicles UD C 62 1 : 62 1 4: 62 882 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy BS AU 0-2.3:1 994 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Automobile Standards Policy Committee (AUE/- ) to Technical Committee AUE/4, upon which the following bodies were represented: Agricultural Engineers’ Association Automobile Association British Industrial Truck Association British Pressure Gauge Manufacturers’ Association British Rubber Manufacturers’ Association Bus and Coach Council Department of Transport Freight Transport Association Institute of Road Transport Engineers (Inc) Motor Cycle Industry’s Association of Great Britain Ltd Motor Industry Research Association National Tyre Distributors’ Association Retread Manufacturers’ Association Road Haulage Association Ltd Society of Motor Manufacturers and Traders Ltd This British Standard, having been prepared under the direction of the Automobile Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on Amendments issued since publication January 994 © BSI 0- 999 The following BSI references relate to the work on this standard: Committee reference AUE/4 Draft for comment 92/85495 DC ISBN 80 223 42 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy Amd No Date Comments BS AU 0-2.3:1 994 Contents Page Committees responsible Inside front cover Foreword iii Section Specification Scope References 3 Definitions Information and requirements to be agreed and to be documented Surface condition Captive washers for spigot- type wheel- nuts Materials Forming of bolts and studs Coatings and surface treatments Thread form and quality 1 Dimensions 3 Testing 3 Disposal of tested components Performance Documentation Marking and identification Annex A (normative) Dimensions of DIN spherical- faced (spherical collar) nuts (type A) 10 Annex B (normative) Quality 10 Annex C (normative) Proof test for flat- faced nuts 11 Annex D (normative) Proof test for conical- faced and spherical- faced nuts 12 Annex E (normative) Proof test for studs and bolts 14 Annex F (normative) Wedge test for bolt heads and stud collars 15 Annex G (normative) Torque/clamping- force test for flat- faced nut type fixings 18 Annex H (informative) Torque/clamping- force test for conical- faced and spherical- faced nut type fixings 20 Figure — Dimensions of flat- faced nuts Figure — Dimensions of conical- faced nuts Figure — Critical dimensions of studs Figure — Critical dimensions of bolts Figure A — Dimensions of DIN spherical- faced (spherical collar) nuts (type A) 10 Figure C — Proof test for flat- faced nuts 12 Figure D — Adaptors for proof testing conical- faced and spherical- faced nuts and all studs and bolts 13 Figure F — Wedge test for bolt- heads 17 Figure F — Wedge test for stud- collars 18 Figure G — Torque/clamping- force test for nuts, bolts, and studs for flat- faced nut type fixings 19 Figure H — Torque/clamping force test for nuts, bolts and studs for conical- faced and spherical- faced nut type fixings © BSI 0- 999 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy 21 Table — Dimensions of flat- faced nuts Table — Dimensions of conical- faced nuts i BS AU 0-2.3:1 994 Page Table — Critical dimensions of studs Table — Critical dimensions of bolts Table A — Dimensions of DIN spherical- faced (spherical collar) nuts (type A) 10 Table C — Proof test for flat- faced nuts 11 Table D — Proof test for conical- faced and spherical- faced nuts and all studs and bolts 13 Table F — Dimensions of wedges 15 Table F — Applied forces for the wedge test 16 Table G — Torque/clamping- force performance for flat- faced nut type fixings 20 Table H — Torque/clamping- force performance for conical- faced nut type fixings 22 Table H — Torque/clamping- force performance for spherical- faced nut type fixings List of references ii Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy 22 Inside back cover © BSI 0- 999 BS AU 0-2.3:1 994 Foreword This s ection of BS AU has b een p rep ared under the direction of the Automob ile S tandards Policy C ommittee, and it forms p art of the s eries of documents which relate to tyres and wheels for motor vehicles There has b een no attemp t to fully define road- wheel comp onents in a des ign- res trictive s ense, b ut neces s ary requirements are sp ecified to achieve s ecure fixing of commercial vehicle road- wheels First, in order to imp rove the alignment and fit of mating p arts, certain imp ortant dimens ions with tolerances have b een s p ecified in this document for fixings, and a new s ize of mm, which is already in limited us e, has b een introduced The corres p onding tolerances on wheel dimensions have b een introduced in B S AU - S econdly, p erformance requirements for nuts , s tuds , and b olts are s p ecified to s uit the sp ecialized s hap es of wheel- fixings to ens ure b oth adequate mechanical s trength and rep eatab le torque/clamp ing- force characteristics during long p eriods of op eration and rep eated vehicle servicing H owever, reference has b een made to existing BS fastener s p ecifications for the maj ority of p erformance tes ts It is exp ected that studs and b olts will, in general, b e formed b y forging and rolling, and this is the recommended method of manufacture Als o in connection with road- wheel s ecurity, attention is drawn to BS AU 0- Code of practice for the selection and care of wheels for commercial vehicles Tyre, wheel, rim and valve requirements ore given in the following p arts and s ections of BS AU : — Part 1: Tyres; — Section 0: General; — Section 1: Car tyres; — Section 2: Commercial vehicle tyres; — Section 3: Off-the-road tyres; — Section 4: Agricultural tractor and machine tyres; — Section 5d: Industrial vehicle tyres; — Section 6: Motorcycle tyres; — Section 7: Moped tyres; — Section 8: Code of practice for the storage of tyres, inner tubes and flaps; — Part 2: Wheels and rims; Section 0: General (including terms and definitions, and construction and workmanship); — — Section 1b: Rim profiles and dimensions (including openings for valves); Section 2: Specification for dimensions of wheel naves and hub centres for commercial vehicles; — Section 3: Specification for road-wheel nuts, studs and bolts for commercial vehicles; — — Section 4: Not published; — Section 5b: Road wheels manufactured wholly or partly of cast light alloy for passenger cars; — Section 6: Specification for road wheels manufactured wholly or partly of light alloy for mopeds and motor cycles; Section 7: Code of practice for the selection and care of wheels for commercial vehicles; — Section 8: Code of practice for the selection and care of wheels for passenger cars (including caravans and light trailers); — — © BS I - 9 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy Part 3: Valves; iii BS AU 0-2.3:1 994 — Section : Specification for valve dimensions; — Section 2: Tyre valve threads 5V1 , 5V2, 6V1 and 8V1 ; — Section 3: Tyre valve threads 9V1 , 0V2, 2V1 and 3V1 ; — Section 4a: Tyre valve threads 8V2, 0V1 , 1 V1 , 13V2, 15V1, 16V1, 17V1, 7V2, 7V3, 9V1 and 20V1 ; — Section 5: Dimensions for ISO core chamber No for tyre inflation valves; — Section 6: Dimensions for ISO core chamber No for tyre inflation valves; Section 7: Code of practice for the selection and care of tyre inflation valves for passenger cars (including caravans and light trailers); — Section 8: Code of practice for the selection and care of tyre inflation valves for commercial vehicles; — — Part 4: Rim profiles and dimensions; — Section 0: General; — Section : Car rims; — Section 2: Commercial vehicle rims; — Section 3: Off-the-road rims; — Section 4: Agricultural tractor and machine rims; — Section 5: Industrial vehicle rims; — Section 6: Motorcycle rims; — Section 7: Moped rims 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 itself confer immunity from legal obligations Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, pages to 22, 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 indicated in the amendment table on the inside front cover iv Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy © BSI 0- 999 BS AU 0-2.3:1 994 Section Specification 3.1 Scope 3.3 Definitions This Section of BS AU 50- specifies dimensions For the purposes of this Section of BS AU 50- 2, the and performance requirements for a range of sizes of following definitions apply: wheel and hub nuts, bolts, and studs for road vehicles The range of sizes covered is normally used on heavy commercial vehicles, but if used on other types of vehicle the requirements of this standard are still applicable This standard does not cover back- nuts which are used to secure certain types of stud to wheel- hubs 3.3.1 nut hexagonal component with an axial, threaded hole and with its intended contact face of conical shape, spherical shape, or carrying a flat- faced, captive washers; used to secure the road- wheel to the hub but it does cover that part of the stud on which the 3.3.2 back- nut fits captive washer The standard is applicable to fasteners for washer secured to a nut so as to prevent loss of the spigot- located wheels washer but to permit rotation of the nut on the employing mm, 20 mm, 22 mm, and 24 mm washer about the axis of the thread studs with hexagonal nuts fitted with flat- seating, 3.3.3 captive washers (type A mounting) , cone- fixings bolt of mm, 7/8 in British Standard Fine (BSF), and in BSF sizes (type B mounting) , and spherical- faced nuts for mm, 20 mm and 22 mm sizes NOTE Mounting types A and B are defined in BS AU 50- 2 BSF threads are specified in BS 84, which is obsolescent, and such threads should be used only for replacement components for externally threaded fixing with a head on one end and usually with a portion of unthreaded shank adj acent to the head 3.3.4 stud existing vehicles Spherical- faced nuts are specified in externally threaded component with threads at both DIN 74361 and dimensional details are given in Annex A ends and usually with a flat- faced, cone- faced, or In addition to the definitive requirements, this spherical- faced collar near to the centre portion standard also requires the items listed in 3.4 to be 3.3.5 documented For compliance with this standard, critical dimensions both the definitive requirements and the documented items have to be satisfied 3.2 References 3.2.1 Normative references This Section of BS AU 50- incorporates, by reference, provisions from 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 Section of BS AU 50- only when incorporated in it by dimensions which ensure interchangeability and avoid the creation of features likely to result in poor fatigue strength 3.3.6 clamping force the force which is applied by the bearing face of the fastener against a mating component after application of a specified tightening torque 3.4 Information and requirements to be agreed and to be documented The following items to be agreed between the updating or revision contracting parties, which are specified in the 3.2.2 Informative references clauses referred to, shall be fully documented Both This Section of BS AU 50- refers to other publications that provide information or guidance The editions of these publications current at the time of issue of this standard are listed on the inside the definitive requirements specified throughout this Section of BS AU 50- and the following documented items shall be satisfied before a claim of conformity can be made and verified: back cover, but reference should be made to the a) the type of stud or bolt material, latest editions i e through- hardened or case- hardened (see 3.7 ) ; b) special coatings of nuts, studs or bolts (see 3.9 ) ; c) any lubrication requirements (see 3.1 4.5 ) ; d) the sampling rates for design evaluation and conformity of production (see B.1 , B.2 ) © BSI 0- 999 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy BS AU 0-2.3:1 994 3.5 Surface condition Nuts and captive washers, bolts, and studs shall be free from loose scale and corrosion Nuts shall conform to BS EN 493: 992 in respect of surface discontinuities For fillet radii having a 90 ° arc, the sizes shall conform to Table and Table of 3.1 , which are sizes equivalent to those in ISO 885: 976 Where fillet radii need to be undercut to prevent interference with the corners of mating holes, such radii shall be formed axially into the face of the head Bolts and studs shall conform to or collar rather than radially into the shank BS EN 261 57- 3: 992 in respect of surface (see also 3.1 ) discontinuities NOTE Heads and collars should preferably be formed by hot or cold forging, and machining of such features from blanks or 3.6 Captive washers for spigot-type wheel-nuts Nuts intended for spigot- type wheels shall incorporate a captive washer Where a captive washer is retained on the nut by means of a swaged, thin- wall extension to the nut, such swaging shall: a) be free from splits; b) securely retain the washer; c) permit the washer sufficient general freedom bar- stock should be permitted only by special agreement between the stud/bolt manufacturer and the vehicle or hub manufacturer, or, in the case of obsolete designs where the vehicle manufacturer is no longer in business, by special agreement between the stud/bolt manufacturer, the component supplier, and the user NOTE Screw threads and spline serrations should preferably be formed by rolling If threads or splines are to be machine- cut and either left in a machined state or finished by rolling, this should be permitted only by special agreement between the stud/bolt manufacturer and the vehicle or hub manufacturer, or, in the case of obsolete designs where the vehicle manufacturer is no longer in business, by special agreement between the stud/bolt manufacturer and the component distributor such that the self- aligning properties of the nut 3.9 Coatings and surface treatments on the washer are not impaired If the purchaser requires studs, bolts or nuts to be 3.7 Materials coated or to have a special surface treatment, the type of coating or treatment required shall be fully 3.7.1 Bolts and studs documented (see 3.4 ) 3.7.1 Through-hardened and tempered In order to avoid delayed brittle fracture, parts with materials The material shall conform to either condition V of BS 970- : 991 or BS 970- 3: 991 or property class of BS EN 20898- : 992 (see 3.4 ) 3.7.1 Case-hardened materials For bolts requiring high surface hardness, case- hardened or surface- hardened steels shall be used (see 3.4 ) The metallurgical conditions after heat- treatment shall be: a) surface hardness between 380 HV and 500 HV 5; b) case depth 25 mm maximum; c) core hardness between 300 HV 30 and 380 HV 30 3.7.2 Nuts Nuts shall be made of steel conforming to either condition U of BS 970- : 991 or property class of BS EN 20898- 6: 992 a surface hardness greater than 390 HV shall not be subj ected to acidic processes or be electro- plated, and parts with a surface hardness of 320 HV to 390 HV shall be baked after electroplating in accordance with ISO 4042: 989 NOTE Certain coatings, either metallic or organic, reduce friction which improves the efficiency of screw threads However, some types of coating, particularly metal plating, can have an adverse effect on thread efficiency when applied similarly to mating parts (i e studs and nuts, or nuts and captive washers) Therefore, the torque/clamping- force tests and the corrosion- resistance tests specified in 3.1 4.5 and 3.1 4.6 , respectively, of this Section of the standard should be used to evaluate the effects of such treatments 3.1 Thread form and quality 3.1 0.1 Metric threads The thread forms and tolerances shall be as defined in BS 3643- 2: 981 , tolerance classes g and H 3.1 0.2 BSF threads The thread forms and tolerances shall be as defined in BS 84: 956, medium class 3.1 0.3 Gauging 3.8 Forming of bolts and studs Thread forms and dimensions shall be gauged In any manufacturing operation, a smooth fillet before the application of any protective or radius shall be formed at the j unction of any head or lubricative coating collar with the shank Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy © BSI 0- 999 BS AU -2 : 994 1 D imensions 1 Nuts with conical face s 1 Nuts with flat-se ating, cap tive washe rs The principal dimensions and tolerances shall be as The principal dimensions and tolerances shall be as given in Figure and Table The cone axis shall b e concentric with the axis of the given in Figure and Tab le The captive washer shall have sufficient swivelling action or the assembly shall be suitably accurate to ensure that the wheel contact face of the washer is thread within 006 in The cone axis shall be parallel with the axis of the thread within ½ perpendicular to the axis of the thread within ½ NO TE The dimensions refer to Tab le Figure — D ime nsions of flat-face d nuts © BSI 0- 999 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy BS AU 0-2.3:1 994 Table — Dimensions of flat-faced nuts D imens ions in millimetres A Thread size B C D E F G max min 8d a R R II max –0 M1 M2 M2 M2 a b × × × × 1.5 27 31 23 40 5 4 27 1.5 30 26 45 5 0 29 1.5 32 37 28 49 34 36 42 31 53 5 36 b Nominal dimens ion I S O 7 : 99 s p ecifies 3 mm for this dimens ion and either s iz e is p ermis s ib le, b ut mm m ay b e p referab le for exis ting vehicles NO TE The dimens ions refer to Tab le Figure — Dimensions of conical-faced nuts Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy © BS I - 99 BS AU 50-2.3:1 994 B.2 Conformity of production Nuts, studs, and bolts shall be examined and tested in accordance with 3.1 2.2 by either the component manufacturer or purchaser The sampling rate shall be agreed between the component manufacturer and the purchaser (see 3.4), and in no case shall the rate of testing be less than one component of each type per production batch Should failure occur during any one test carried out in accordance with 3.1 2.2 , the production batch from which the samples were taken shall be set aside and an investigation carried out to determine the cause of failure If the dimensional accuracy of the failed component is satisfactory then it shall be subjected to an investigation of mechanical and metallurgical properties, the cause of the failure determined and the batch re-examined If the cause of failure cannot be determined, then six more components shall be subjected to the test which produced failure If any one of the six fails, the complete batch shall be deemed not to conform to this standard Annex C (normative) Proof test for flat-faced nuts C.1 Principle A compressive load is induced in the nut/washer assembly in order to determine whether or not the washer has adequate crush strength, the threads have adequate crush and shear strength, and the body of the nut has adequate general strength C.2 Apparatus NOTE The apparatus is shown in Figure C.1, and the preferred tensile loading is indicated C.2.1 to the threaded mandrel (C.2.2 ) such as to induce a compressive load in the nut/washer assembly The accuracy of the applied force (see Table C.1), as determined by a suitable means of calibration traceable to national standards, shall be within ± % of its nominal value Means of ap p lying axial tensile o r co m p ress iv e fo rce, F Table C.1 — Proof test for flat-faced nuts Thread size Applied forces Initial force, F kN M18 × 1.5 M20 × 1.5 M22 × 1.5 M24 × 2.0 0.6 Test force F kN 141 235 180 300 216 360 279 465 C.2.2 having threads typical of the form and tolerance class of the bolt or stud to be used with the nut in production and of steel with a hardness of not less than HV 450 C.2.3 of steel of hardness not less than HV 450 Threaded m andrel, Fixed sup p o rt- p late, C.3 Test component The test component shall be a nut with a captive, flat-faced washer sampled in accordance with B.1 or B.2 C.4 Procedure Screw the nut on to the mandrel with hand-force only and locate the resulting assembly through the plate Measure the unloaded height of the nut/washer assembly, , in millimetres (see Figure C.1) Apply an axial force of 0.6 (see Table C.1) by either tension or compression to the mandrel to load the nut against the plate; maintain this force for 15 s and then fully release it Repeat this loading sequence twice more, and then apply a fourth loading of the full value of and maintain it for 15 s before it is released Measure the unloaded height of the nut/washer assembly, , in millimetres Unscrew the nut from the mandrel by hand, if possible [see 3.1 4.1 c)] H F F H © BSI 10-1999 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy 11 BS AU 50-2.3:1 994 Figure C.1 — Proof test for flat-faced nuts Annex D (normative) Proof test for conical-faced and spherical-faced nuts D.1 Principle A compressive load is induced in the nut to determine whether or not the body of the nut has adequate general strength and the threads have adequate crush and shear strength D.2 Apparatus NOTE Special fittings for use with the test apparatus are shown in Figure D.1 to a threaded mandrel (D.2.2 ) such as to induce a compressive load in the nut The accuracy of the applied force (see Table D.1), as determined by a suitable means of calibration traceable to national standards, shall be within ± % of its nominal value D.2.2 having threads typical of the form and tolerance class of the bolt or stud to be used with the nut in production and of steel with a hardness of not less than HV 450 (or 45 HRC minimum) D.2.3 of steel of hardness not less than HV 450 D.2.1 Means of ap p lying axial tens ile o r com p ressiv e force, F Threaded m andrel, Fixed p late suitab ly shap ed to suit the face of the nut, D.3 Test component The test component shall be a conical-faced or spherical-faced nut sampled in accordance with B.1 or B.2 D.4 Procedure Screw the nut on the threaded mandrel with hand-force only and assemble it in the test machine with the conical or spherical face located in the appropriate plate (Figure D.1) 12 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy © BSI 10-1999 BS AU 0-2.3:1 994 Apply the proof load F and maintain it fully for s Table D.1 — Proof test for conical-faced and spherical-faced nuts and all studs and bolts Thread size Applied force Nuts a kN ×1.5 M2 × M2 × M2 × M1 × M1 kN — 68 — 21 — 59 — 99 213 53 7/8 in BSF 31 227 in BSF 41 301 a F Bolts or studs See Tab le C for flat- faced nuts Figure D.1 — Adaptors for proof testing conical-faced and spherical-faced nuts and all studs and bolts © BSI 0- 999 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy 13 BS AU 50-2.3:1 994 NOTE Typical arrangements shown NOTE Depths of spherical-seatings and conical-seatings and clearances of nut-adaptors on threaded mandrels typical of wheel naves (see BS AU 50-2.2) Figure D.1 — Adaptors for proof testing conical-faced and spherical-faced nuts and all studs and bolts (concluded) Annex E (normative) Proof test for studs and bolts E.1 Principle A tensile load is induced in the stud or bolt to determine whether or not the component has adequate tensile strength E.2 Apparatus NOTE Special fittings for use with the test apparatus are shown in Figure D.1 Means of applying axial tensile force, to threaded plate(s) or nut(s) (E.2.2 ) and/or the bolt head such as to induce a tensile load in the stud or bolt The machine shall have suitable self-aligning heads to ensure axial loading and shall have a free-running cross-head to provide a test speed not exceeding mm/min The accuracy of the applied force F2 (see Table D.1), as determined by a suitable means of calibration traceable to national standards, shall be within ± % of its nominal value E.2.2 Threaded nuts or plates, having threads typical of the form and tolerance class of the nut(s) to be used with the stud or bolt in production and of steel with a hardness of HV 450 minimum (or 45 HRC minimum) The thickness of the nuts or plates shall be equal to the minimum for production nuts E.2.3 Fixed plate, of steel of hardness of HV 450 minimum (or 45 HRC minimum) to support the head of a bolt E.2.4 Means of measuring stud or bolt length, comprising a bench-mounted instrument fitted with spherical anvils and gloves or tongs for handling the stud or bolt E.2.1 E.3 Test component The test component shall be a stud or bolt sampled in accordance with B.1 or B.2 , and to permit measurement of permanent extension, it shall be axially centre-drilled (60° cone) at each end 14 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy © BSI 10-1999 BS AU 50-2.3:1 994 E.4 Procedure Pass the stud or bolt through the test assembly and screw the wheel-retaining nut or equivalent plate on with hand-force only until all of the threads of the nut or plate are engaged, but no threads shall project beyond the outer face of the nut or plate In the case of a stud which is secured by a back-nut, screw a threaded block on to the thread intended for the back-nut and tighten it fully to the vehicle manufacturer’s recommended torque before fitting the wheel-retaining nut or threaded plate Apply the proofing force, 2, and maintain it fully for 15 s After releasing the proofing force, measure the stud or bolt length using the bench-mounted instrument The gloves or tongs are used to minimize measurement error F Annex F (normative) Wedge test for bolt heads and stud collars F.1 Principle A force parallel to the axis of the thread is applied to the edge of the head of a bolt or the collar of a stud to ensure integrity under misalignment in service F.2 Apparatus NOTE The special fittings and the test arrangements are shown in Figure F.1 and Figure F.2, and dimensions of fittings are given in Table F.1 and F.2.2 Table F.1 — Dimensions of wedges Nominal shank D diameter, d s t B r ± 0.3 ± 30 degrees d mm 18 20 22 24 54 60 66 72 in 7/8 mm ± 0.3 19.6 21.6 23.6 27.2 mm 66 76 mm ± 0.3 mm 9.0 10 11 12 mm ± 0.3 mm ± 0.13 ½ 10 10 6 ± 30 degrees ½ 1.3 1.3 1.6 1.6 mm ± 0.13 mm 23.8 11 1.6 28.6 13 1.6 F.2.1 to a test fixture so as to induce a compressive/bending load to the face of a bolt head or a stud collar in contact with a wedge-shaped plate, and of maintaining the axis of the hole in the wedge in line with the axis of the tensile force at all times The accuracy of the maximum applied force (see Table F.2) as determined by a suitable means of calibration traceable to national standards, shall be within ± % of its nominal value F.2.2 manufactured of steel with a hardness HV 600 minimum (or 55 HRC minimum) and with dimensional details as specified in Table F.1 and as follows: If the shank diameter, s, of the stud or bolt is greater than the nominal thread diameter, then the wedge dimensions shall be calculated thus: = s + 1.6 mm for s < 20 mm = s + 3.2 mm for s > 20 mm = s + 0.63 in for s > 7/8 in = 0.5 × s = 10 for s < 20 mm = for s > 20 mm = 1.3 mm for s < 20 mm = 1.6 mm for s > 20 mm = 0.063 in for s > 7/8 in Means of ap p lying tensile force, F Wedge, d d d d d d d t B d d d d r d d d NOTE The dimension © BSI 10-1999 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy D is for guidance to ensure a strong wedge and the recommended size is D = × s d 15 BS AU 0-2.3:1 994 F.3 Test component A stud with a collar or a bolt sampled in accordance with B.1 or B.2 F.4 Procedure Assemble the bolt or stud on the wedge as shown in Figure F or Figure F 2, respectively, with hexagonal or D- shaped heads orientated as shown in Figure F c) Apply a steadily- increasing tensile force to the shank of the bolt or stud until a maximum value of attained (see Table F 2) For special fixings with shank diameters greater than the thread diameter, the value of the force F F is shall be that appropriate to the thread diameter For stepped studs, the force F shall be that appropriate to the greater thread diameter Table F.2 — Applied forces for the wedge test Thread size Applied force kN × × M22 × M24 × 1.5 325 375 × 97 M1 1.5 21 M20 1.5 266 M1 7/8 in BSF 293 in BSF 386 16 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy F © BSI 0- 999 BS AU 0-2.3:1 994 NO TE The dimensions refer to Tab le F Figure F.1 — Wedge test for bolt-heads © BSI 0- 999 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy 17 BS AU 50-2.3:1 994 NOTE Typical arrangement shown NOTE For wedge details see Figure F.1 b) NOTE Asymmetric collars should be located for maximum bending as for bolt-heads, see Figure F.1 c) Figure F.2 — Wedge test for stud collars Annex G (normative) Torque/clamping-force test for flat-faced nut type fixings G.1 Principle A repeated torque is applied to a nut assembled on a hardened threaded mandrel, to a stud or bolt assembled in a special hardened threaded fixture, or to a nut/bolt assembly, and the repeatability of the clamping-force generated by the torque over a number of operations is determined Tests on assemblies of production nuts and studs or bolts are only conducted after satisfactory performance has been obtained on similar, individual components from the same production batch tested in conjunction with the special fixtures G.2 Apparatus NOTE The apparatus is shown in Figure G.1 G.2.1 to a nut or a bolt-head so as to induce tension in the male threaded component and compression in the assembly The applied torque and the clamping-force (see Table G.1) as determined by a suitable means of calibration traceable to national standards, shall be within ± % of their nominal values G.2.2 typical of the male and female threaded portions of production fasteners manufactured of steel with a hardness of 450 HV minimum (or 45 HRC minimum) Means of ap p lying torq ue, T C Threaded test fixtures , NOTE The female threaded fixtures may be plates or simulated wheel-nuts G.2.3 Means of m easuring G.2.4 Means of m easuring the applied torque the induced clamping-force in the assembly NOTE Preferably, the machine shall incorporate an X-Y plotter connected to appropriate transducers to continuously record the torque and clamping-force relationship G.3 Test components A stud, a bolt, or a nut sampled in accordance with B.1 or B.2 18 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy © BSI 10-1999 BS AU -2 : 994 G Procedure G Assembly G Nuts Pass the threaded mandrel through the test fixture and screw on the nut using hand- force only until all of the nut threads are engaged G Studs or bolts Pass the stud or bolt through the test fixture and screw on the threaded plate or the simulated wheel- nut using hand- force only until all of the nut/plate threads are engaged In the case of a stud which is secured with a back- nut, screw on the back- nut and tighten it fully to the manufacturer’s recommended torque before the nut or threaded plate is fitted NOTE Typical arrangement shown NOTE Replaceable washers should simulate the appropriate types of wheel as shown in the relevant standard (see BS AU 50- 2) Figure G — Torque /clamping-force test for nuts, b olts and studs for flat-face d nut typ e fixings G Nut and stud bolt assemblies / Pass the stud or bolt through the test fixture and screw on the wheel- nut using hand- force only until all of the nut threads are engaged, in the case of a stud which is secured with a back- nut, screw on the back- nut and tighten it fully to the manufacturer’s recommended torque before the wheel- nut is fitted G Replaceable washers for contacting the nut face A new washer shall be used for each test on a new nut G Application of torque Tighten the wheel- nut or the nut/plate progressively at a steady rate with a rotational speed of not more than r/min until the appropriate torque value of T is attained, as specified in Table G Record the clamping- force and then fully release the torque and run off the nut or nut/plate until only two threads remain engaged with the stud, bolt or mandrel © BSI 0- 999 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy 19 BS AU 50-2.3:1 994 Table G.1 — Torque/clamping-force performance for flat-faced nut type fixings Thread size Applied torque Clamping force T M18 × 1.5 M20 × 1.5 M22 × 1.5 M24 × 2.0 N·m 320 450 600 795 kN max kN C 120 156 190 241 C 151 196 240 303 NOTE The torque values specified for these tests are for determination of quality only, and are not to be taken as values recommended for use in service Before re-tightening, closely inspect the threads and contact-faces for the presence of swarf or other debris and remove as necessary Repeat this tightening and releasing action until a total of one hundred operations has been completed allowing a pause of not less than 100 s between release and re-tightening, recording the clamping-force on each occasion and applying a lubricant, if necessary, to obtain a clamping-force within the specified range, to max C C NOTE The pause has been found necessary to avoid the creation of excessive, frictional heating Keep a record of whether or not it has been necessary to apply a lubricant to achieve a clamping-force within the specified range and, if used, the type of lubricant and the parts of the assembly to which it is applied (see also 3.1 4.5 ) Annex H (informative) Torque/clamping-force test for conical-faced and spherical-faced nut type fixings H.1 Principle A repeated torque is applied to a nut assembled on a hardened threaded mandrel, to a stud or bolt assembled in a special hardened threaded fixture, or to a nut/bolt assembly, and the repeatability of the clamping-force generated by the torque over a number of operations is determined Tests on assemblies of production nuts and studs or bolts are only conducted after satisfactory performance has been obtained on similar, individual components from the same production batch tested in conjunction with the special fixtures H.2 Apparatus NOTE The apparatus is shown in Figure H.1 to a nut or a bolt-head so as to induce tension in the male threaded component and compression in the assembly The applied torque and the clamping-force (see Table H.2) as determined by a suitable means of calibration traceable to national standards, shall be within ± % of their nominal values H.2.2 typical of the male and female threaded portions of production fasteners manufactured of steel with a hardness of 450 HV minimum (or 45 HRC minimum) H.2.1 Means o f ap p lying torq ue, T C Threaded tes t fixtures, NOTE The female threaded fixtures may be plates or simulated wheel-nuts H.2.3 Means of m easuring H.2.4 Means of m easuring the applied torque the induced clamping-force in the assembly NOTE Preferably, the machine should incorporate an X-Y plotter connected to appropriate transducers to continuously record the torque and clamping-force relationship H.3 Test components A stud, a bolt, or a nut sampled in accordance with B.1 or B.2 20 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy © BSI 10-1999 BS AU -2 : 994 H Proce dure H.4.1 Assembly H.4.1 Nuts Pass the threaded mandrel through the test fixture and screw on the nut using hand- force only until all of the nut threads are engaged NOTE Typical arrangement shown NOTE Replaceable washers should simulate the appropriate types of wheel as shown in the relevant standard (see BS AU 50- 2) Figure H — Torque /clamp ing-force te st for nuts, b olts and studs for conical-face d and spherical-faced nut typ e fixings H.4.1 Studs or bolts Pass the stud or bolt through the test fixture and screw on the threaded plate or the simulated wheel- nut using hand- force only until all of the nut/plate threads are engaged In the case of a stud which is secured with a back- nut, screw on the back- nut and tighten it fully to the manufacturer’s recommended torque before the nut or threaded plate is fitted H.4.1 Nut and stud bolt assemblies / Pass the stud or bolt through the test fixture and screw on the wheel- nut using hand- force only until all of the nut threads are engaged In the case of a stud which is secured with a back- nut, screw on the back- nut and tighten it fully to the manufacturer’s recommended torque before the wheel- nut is fitted H.4.1 Replaceable washers for contacting the nut face A new washer shall be used for each test on a new nut H.4.2 Application of torque Tighten the wheel- nut or the nut/plate progressively at a steady rate with a rotational speed of not more than r/min until the appropriate torque value of T is attained, as specified in Table H or Table H Record the clamping- force and then fully release the torque and run off the nut or nut/plate until only two threads remain engaged with the stud, bolt or mandrel © BSI 0- 999 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy 21 BS AU 0-2.3:1 994 Table H.1 — Torque/clamping-force performance for conical-faced nut type fixings Thread size Applied torque C lamping-force T C C N·m M1 × NOTE kN 41 110 29 680 30 53 060 70 200 7/8 in BSF in BSF max kN The torque values specified for these tests are for determination of quality only, and are not to be taken as values recommended for use in service Table H.2 — Torque/clamping-force performance for spherical-faced nut type fixings Thread size Clamping force Applied torque T C C max N·m M1 M20 M22 × × × NOTE kN kN 1.5 41 110 29 1.5 540 28 51 1.5 650 50 76 The torque values specified for these tests are for determination of quality only, and are not to be taken as values recommended for use in service Before re- tightening, closely inspect the threads and contact- faces for the presence of swarf or other debris and remove as necessary Repeat this tightening and releasing action until a total of one hundred operations has been completed allowing a pause of not less than 00 s between release and re- tightening, recording the clamping- force on each occasion and applying a lubricant, if necessary, to obtain a clamping- force within the specified range, NOTE C to C max The pause has been found necessary to avoid the creation of excessive, frictional heating Keep a record of whether or not it has been necessary to apply a lubricant to achieve a clamping- force within the specified range and, if used, the type of lubricant and the parts of the assembly to which it is applied (see also 3.1 4.5 ) 22 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy © BSI 0- 999 BS AU 0-2.3:1 994 List of references (see clause ) Normative references BSI standards publications BRITISH STANDARDS INSTITUTION, London BS 84: 956, BS 970, Sp ecificatio n for p arallel screw threads of Whitw orth form Sp ecification for w rought steels for m echanical and allied engineering p urp oses BS 970- : 991 , m anganes e, BS 970- 3: 991 , BS 3643, General insp ection and testing p ro cedures and sp ecific req uirem ents for carb on, carb on alloy and s tainless steels Bright b ars for general engineering p urp o ses ISO m etric screw threads BS 3643- 2: 981 , Sp ecification for selected lim its of size BS EN 493: 992, BS EN 20898, Fasteners — Surface discontinuities — Nuts Mechanical p rop erties of fas teners BS EN 20898- : 992, Bolts, BS EN 20898- 6: 992, Nuts w ith s p ecified p roo f load v alues BS EN 261 57, Fas teners BS EN 261 57- 3: 992, screw s and studs Fine p itch thread Surface disco ntinuities Bolts , screw s and s tuds for s p ecial req uirem ents ISO publications INTERNATIONAL ORGANIZATION FOR STANDARDIZATION (ISO) Geneva (All publications are available from Customer Services Publications, BSI ) ISO 4042: 989, Threaded com p o nents — electrop lated coatings ISO 7575: 993, Ro ad vehicles — Wheels for com m ercial v ehicles — Flat attachm ent — Fixing nuts DIN publication DEUTSCHES INSTITUT FUR NORMUNG e V , Berlin All publications are avaliable from Customer Services, Publications, BSI ) DIN 74 361 - 2: 982, Disc w heels fo r m o to r v ehicles and trailers ; fastening devices for b olt centering Informative references BSI standards publications BRITISH STANDARDS INSTITUTION, London BS AU 50, Tyres and w heels BS AU 50- 2, Wheels and rim s BS AU 50- 2: 984, Sp ecificatio n for dim ensions o f w heel nav es and hub centres for co m m ercial v ehicles BS AU 50- 7: 987, Co de o f p ractice for the selection and care of w heels fo r co m m ercial v ehicles ISO publication INTERNATIONAL ORGANIZATION FOR STANDARDIZATION (ISO) Geneva (All publications are available from Customer Services, Publications, BSI ) ISO 885: 976, General p urp o se b olts and screw s — Metric series — Radii under the head © BSI 0- 999 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy BS AU 50-2.3: 994 BSI — British Standards Institution BS I is the indep endent national b ody res p ons ib le for p rep aring Britis h S tandards It p res ents the UK view on s tandards in E urop e and at the international level It is incorp orated b y Royal C harter Revisions Britis h S tandards are up dated b y amendment or revis ion Us ers of Britis h S tandards should make s ure that they p oss es s the latest amendments or editions It is the constant aim of BS I to imp rove the quality of our p roducts and services We would b e grateful if anyone finding an inaccuracy or amb iguity while us ing this Britis h S tandard would inform the S ecretary of the technical committee res p ons ib le, the identity of which can b e found on the inside front cover Tel: 02 89 96 90 00 Fax: 02 89 96 40 BS I offers memb ers an individual up dating s ervice called PLUS which ens ures that s ub s crib ers automatically receive the lates t editions of s tandards Buying standards O rders for all BS I, international and foreign s tandards p ub lications s hould b e addres s ed to C us tomer S ervices Tel: 899 00 Fax: 899 7001 In res p ons e to orders for international standards , it is BS I p olicy to sup p ly the BS I imp lementation of thos e that have b een p ub lis hed as Britis h S tandards, unless otherwis e requested Information on standards BS I p rovides a wide range of information on national, E urop ean and international standards through its Lib rary and its Technical H elp to E xp orters S ervice Various BS I electronic information s ervices are also availab le which give details on all its p roducts and s ervices C ontact the Information C entre Tel: 02 89 96 71 1 Fax: 02 89 96 048 S ub s crib ing memb ers of BS I are kep t up to date with s tandards develop ments and receive sub s tantial discounts on the p urchase p rice of s tandards For details of thes e and other b enefits contact Memb ership Adminis tration Tel: 02 89 96 70 02 Fax: 02 89 96 00 Copyright C op yright s ub s is ts in all BS I p ub lications BS I als o holds the cop yright, in the UK, of the p ub lications of the international s tandardization b odies E xcep t as p ermitted under the C op yright, D es igns and Patents Act 988 no extract may b e rep roduced, s tored in a retrieval s ystem or transmitted in any form or b y any means – electronic, p hotocop ying, recording or otherwis e – without p rior written p ermis s ion from BS I This does not p reclude the free us e, in the cours e of imp lementing the standard, of necess ary details such as s ymb ols, and size, typ e or grade designations If thes e details are to b e used for any other p urp os e than imp lementation then the p rior written p ermiss ion of BS I must b e ob tained If p ermis sion is granted, the terms may include royalty p ayments or a licensing agreement D etails and advice can b e ob tained from the C op yright Manager BS I 89 C his wick H igh Road London W4 4AL Reprodu ced by I H S u n d er l i cen se wi th BSI - 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