ISO-3290-2001.pdf

Reference number ISO 3290:2001(E) © ISO 2001 INTERNATIONAL STANDARD ISO 3290 Third edition 2001-12-01 Rolling bearings Balls Dimensions and tolerances Roulements Billes Dimensions et tolérances ISO 3290:2001(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. © ISO 2001 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO's member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.ch Web www.iso.ch Printed in Switzerland ii © ISO 2001 All rights reserved -,-,- ISO 3290:2001(E) © ISO 2001 All rights reserved iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. International Standard ISO 3290 was prepared by Technical Committee ISO/TC 4, Rolling bearings. This third edition cancels and replaces the second edition (ISO 3290:1998) which has been technically revised. Annexes A and B form a normative part of this International Standard. -,-,- INTERNATIONAL STANDARD ISO 3290:2001(E) © ISO 2001 All rights reserved 1 Rolling bearings Balls Dimensions and tolerances 1 Scope This International Standard specifies requirements for finished steel balls for rolling bearings. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 1132-1:2000, Rolling bearings Tolerances Part 1: Terms and definitions ISO 4288:1996, Geometrical Product Specifications (GPS) Surface texture: Profile method Rules and procedures for the assessment of surface texture ISO 4291:1985, Methods for the assessment of departure from roundness Measurement of variations in radius ISO 5593:1997, Rolling bearings Vocabulary ISO 15241:2001, Rolling bearings Symbols for quantities 3 Terms and definitions For the purposes of this International Standard, the terms and the definitions given in ISO 1132-1, ISO 5593 and ISO 15241 and the following apply. 3.1 nominal ball diameter Dw diameter value which is used for the general identification of a ball size 3.2 single ball diameter Dws distance between two parallel planes tangential to the actual surface of a ball 3.3 mean ball diameter Dwm arithmetical mean of the largest and the smallest of the single diameters of a ball -,-,- ISO 3290:2001(E) 2 © ISO 2001 All rights reserved 3.4 variation of ball diameter VDws difference between the largest and the smallest of the single diameters of a ball 3.5 surface irregularities and form parameters various types of deviation from the perfect spherical ball surface, uniformly distributed and repeated around the ball surface NOTE The deviations to which limits can be attributed are: deviation from spherical form; waviness; surface roughness. 3.5.1 deviation from spherical form greatest radial distance, in any equatorial plane, between the smallest circumscribed sphere and the greatest inscribed sphere, with their centres common to the least square sphere centre NOTE Information about the measurement of this deviation is given in annex A. 3.5.2 waviness surface irregularities of random or periodical deviation from the ideal spherical form NOTE It is recommended that waviness be evaluated as velocity amplitude. In practice, the waviness components are separated from the real surface by a waviness analyser (filters). 3.5.3 surface roughness surface irregularities with relatively small spacings, which usually include irregularities resulting from the method of manufacture being used and/or other influences NOTE These irregularities are considered within the limits that are conventionally defined, e.g., within the limits of the sampling length. 3.6 surface defect element, irregularity or group of elements and irregularities of the real surface, unintentionally or accidentally caused during manufacture, storage, handling or use of the surface NOTE These types of element or irregularity differ considerably from those constituting the surface roughness and should not be considered during the measurement of the surface roughness (see 4.2, note 2). Surface defects (and their limits) are not specified in this International Standard. 3.7 ball lot definite quantity of balls manufactured under conditions presumed uniform and which is considered as an entity 3.8 mean diameter of ball lot DwmL arithmetical mean of the mean diameters of the largest ball and the smallest ball in a ball lot -,-,- ISO 3290:2001(E) © ISO 2001 All rights reserved 3 3.9 variation of ball lot diameter VDwL difference between the mean diameters of the largest ball and the smallest ball in a ball lot 3.10 ball grade G specific combination of dimensional, form, surface roughness and sorting tolerances for balls NOTE Ball grade is identified by the letter G and a number. 3.11 ball gauge S amount by which the mean diameter of a ball lot should differ from the nominal ball diameter, this amount being one of an established series NOTE 1 Each ball gauge is a whole multiple of the ball gauge interval established for the ball grade in question (see Table 3 and annex B). NOTE 2 A ball gauge, in combination with the ball grade and nominal diameter, should be considered as the most exact ball size specification to be used by a customer for ordering purposes. 3.12 deviation of a ball lot from ball gauge S difference between the mean diameter of a ball lot and the sum of the nominal ball diameter and the ball gauge () wmLwS DDS=+ See Table 3 and annex B. 3.13 ball subgauge amount of an established series of amounts, which is the nearest to the actual deviation from the ball gauge of a ball lot NOTE 1 Each ball subgauge is a whole multiple of the ball subgauge interval established for the ball grade in question (see Table 3 and annex B). NOTE 2 The ball subgauge, in combination with the nominal ball diameter and the ball gauge, is used by ball manufacturers to denote the mean diameter of a ball lot and should not be used by customers for ordering purposes. 3.14 hardness measure of resistance to penetration as determined by specific methods 4 Requirements 4.1 Ball size The preferred nominal ball diameters are given in Table 1. Where applicable, the corresponding inch sizes are given for reference purposes only. -,-,- ISO 3290:2001(E) 4 © ISO 2001 All rights reserved 4.2 Quality of geometry and surface Requirements for: variation of ball diameter, see Table 2; deviation from spherical form, see Table 2; waviness, see note 1; surface roughness, see Table 2; surface appearance and defects, see note 2. Measurement of surface roughness shall be made in accordance with ISO 4288. NOTE 1 Limits and measuring methods for waviness should be agreed upon between customer and supplier. NOTE 2 Surface appearance characteristics, local defects, scratches and the like are subject to agreement between customer and supplier. 4.3 Sorting accuracy and ball gauges Table 3 comprises the applicable values for: variation of ball lot diameter; gauge interval; preferred gauges; subgauge interval; subgauges. 4.4 Hardness Hardness values and the measuring method shall be agreed upon between customer and supplier. -,-,- ISO 3290:2001(E) © ISO 2001 All rights reserved 5 Table 1 Preferred nominal ball diameters Nominal ball diameter Dw Corresponding inch size (reference) Nominal ball diameter Dw Corresponding inch size (reference) Nominal ball diameter Dw Corresponding inch size (reference) mm in mm in mm in 0,3 9,525 3/830,162 5 1 3/16 0,396 88 1/64 9,921 8825/6431,75 1 1/4 0,4 10 32 0,5 10,318 7513/3233 0,508 0,02 10,5 33,337 5 1 5/16 0,6 11 34 0,635 0,02511,112 5 7/16 34,925 1 3/8 0,68 11,5 35 0,7 11,509 3829/6436 0,793 75 1/32 11,906 2515/3236,512 5 1 7/16 0,8 12 38 1 12,303 1231/6438,1 1 1/2 1,190 62 3/64 12,5 39,687 5 1 9/16 1,2 12,7 1/240 1,5 13 41,275 1 5/8 1,587 5 1/16 13,493 7517/3242,862 5 1 11/16 1,984 38 5/64 14 44,45 1 3/4 2 14,287 5 9/16 45 2,381 25 3/32 15 46,037 5 1 13/16 2,5 15,081 2519/3247,625 1 7/8 2,778 12 7/64 15,875 5/849,212 5 1 15/16 3 16 50 3,175 1/8 16,668 7521/3250,8 2 3,5 17 53,975 2 1/8 3,571 88 9/64 17,462 5 11/1655 3,968 75 5/32 18 57,15 2 1/4 4 18,256 2523/3260 4,365 62 11/6419 60,325 2 3/8 4,5 19,053/463,5 2 1/2 4,762 5 3/16 19,843 7525/3265 5 20 66,675 2 5/8 5,159 38 13/6420,5 69,85 2 3/4 5,5 20,637 5 13/1670 5,556 25 7/32 21 73,025 2 7/8 5,953 12 15/6421,431 2527/3275 6 22 76,2 3 6,35 1/4 22,2257/879,375 3 1/8 6,5 22,5 80 6,746 88 17/6423 82,55 3 1/4 7 23,018 7529/3285 7,143 75 9/32 23,812 5 15/1685,725 3 3/8 7,5 24 88,9 3 1/2 7,540 62 19/6424,606 2531/3290 7,937 5 5/16 25 92,075 3 5/8 8 25,4 1 95 8,334 38 21/6426 95,25 3 3/4 8,5 26,193 751 1/3298,425 3 7/8 8,731 25 11/3226,987 5 1 1/16100 9 28 101,6 4 9,128 12 23/6428,5751 1/8 104,775 4 1/8 9,5 30 -,-,- ISO 3290:2001(E) 6 © ISO 2001 All rights reserved Table 2 Form and surface roughness tolerances Grade Variation of ball diameter VDws max. Deviation from spherical form max. Surface roughness Ra max. G 3 0,08 0,08 0,010 G 5 0,13 0,13 0,014 G 10 0,25 0,25 0,020 G 16 0,4 0,4 0,025 G 20 0,5 0,5 0,032 G 24 0,6 0,6 0,040 G 28 0,7 0,7 0,050 G 40 1 1 0,060 G 60 1,5 1,5 0,080 G 100 2,5 2,5 0,100 G 200 5 5 0,150 NOTE The values given in this table do not take into account surface defects; hence measurement must be taken outside such defects. Table 3 Sorting tolerances and gauges Variation of ball lot diameter VDwL max. Gauge interval Preferred gauges Subgauge interval Subgauges Grade mm G 3 0,13 0,5 - 5, 0,5, 0, + 0,5, + 5 0,1 - 0,2, - 0,1, 0, + 0,1, + 0,2 G 5 0,25 1 - 5, - 1, 0, + 1, . + 5 0,2 - 0,4, - 0,2, 0, + 0,2, + 0,4 G 10 0,5 1 - 9, - 1, 0, + 1, . + 9 0,2 - 0,4, - 0,2, 0, + 0,2, + 0,4 G 16 0,8 2 - 10, - 2, 0, + 2, . + 10 0,4 - 0,8, - 0,4, 0, + 0,4, + 0,8 G 20 1 2 - 10, - 2, 0, + 2, . + 10 0,4 - 0,8, - 0,4, 0, + 0,4, + 0,8 G 24 1,2 2 - 12, - 2, 0, + 2, . + 12 0,4 - 0,8, - 0,4, 0, + 0,4, + 0,8 G 28 1,4 2 - 12, - 2, 0, + 2, . + 12 0,4 - 0,8, - 0,4, 0, + 0,4, + 0,8 G 40 2 4 - 16, - 4, 0, + 4, . + 16 0,8 - 1,6, - 0,8, 0, + 0,8, + 1,6 G 60 3 6 - 18, - 6, 0, + 6, . + 18 1,2 - 2,4, - 1,2, 0, + 1,2, + 2,4 G 100 5 10 - 40, - 10, 0, + 10, . + 40 2 - 4, - 2, 0, + 2, + 4 G 200 10 15 - 60, - 15, 0, + 15, . + 60 3 - 6, - 3, 0, + 3, + 6 -,-,- ISO 3290:2001(E) © ISO 2001 All rights reserved 7 Annex A (normative) Method for assessment of deviation from spherical form Measurement of variations in radius The measurement of deviation from the spherical form of balls shall be carried out by measurement of roundness deviation in a required number of single equatorial planes. The evaluation of roundness in a single equatorial plane may be carried out by calculation from the least square centre. The greatest radial distance in any single equatorial plane is assumed to be the deviation from spherical form. Roundness deviation is measured in three equatorial planes 90° to each other. For a detailed description of methods for the assessment of deviation from roundness see ISO 4291. ISO 3290:2001(E) 8 © ISO 2001 All rights reserved Annex B (normative) Illustration of gauges and sorting principles B.1 Gauge and subgauge Figure B.1 shows an example of gauge and subgauge for grade G5 balls. Values in micrometres a Subgauge interval. b Subgauge scale used by manufacturer. c Gauge scale used by customer. d Gauge interval. e Nominal ball diameter, Dw. Figure B.1 -,-,- ISO 3290:2001(E) © ISO 2001 All rights reserved 9 B.2 Lot and gauge deviation Key 1 Smallest ball in the lot 2 Lot 3 Largest ball in the lot 4 Lot with smallest DwmL to be referred to gauge S 5 Lot with largest DwmL to be referred to gauge S a Variation of ball lot diameter, VDwL. b Variation of ball diameter, VDws. c Mean diameter of ball lot, DwmL. d Subgauge scale. e Gauge scale. f Deviation of a ball lot from ball gauge, DS. g Subgauge to which the lot is referred. h Gauge