BS ISO 725-2009 ISO英寸螺紋標準-基本尺寸

BS ISO 725:2009 ICS 21.040.20 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BRITISH STANDARD ISO inch screw threads — Basic dimensions This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2009. © BSI 2009 ISBN 978 0 580 64569 3 Amendments/corrigenda issued since publication Date Comments BS ISO 725:2009 National foreword This British Standard is the UK implementation of ISO 725:2009. The UK participation in its preparation was entrusted to Technical Committee FME/9, Fasteners. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. BS ISO 725:2009 Reference number ISO 725:2009(E) © ISO 2009 INTERNATIONAL STANDARD ISO 725 Second edition 2009-04-15 ISO inch screw threads — Basic dimensions Filetages ISO en inches — Dimensions de base BS ISO 725:2009 ISO 725:2009(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. COPYRIGHT PROTECTED DOCUMENT © ISO 2009 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 copyright@iso.org Web www.iso.org Published in Switzerland ii © ISO 2009 – All rights reserved BS ISO 725:2009 ISO 725:2009(E) © ISO 2009 – All rights reserved iii Contents Page Foreword............................................................................................................................................................ iv 1 Scope ..................................................................................................................................................... 1 2 Symbols ................................................................................................................................................. 1 3 Basic dimensions ................................................................................................................................. 2 Bibliography ..................................................................................................................................................... 14 BS ISO 725:2009 ISO 725:2009(E) iv © ISO 2009 – All rights reserved 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 2. The main task of technical committees is to prepare International Standards. 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 document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 725 was prepared by Technical Committee ISO/TC 1, Screw threads. This second edition results from the reinstatement of ISO 725:1978, which was withdrawn in 2000 and with which it is technically identical. BS ISO 725:2009 INTERNATIONAL STANDARD ISO 725:2009(E) © ISO 2009 – All rights reserved 1 ISO inch screw threads — Basic dimensions 1 Scope This International Standard specifies the basic dimensions, in inches, of ISO inch screw threads in accordance with ISO 263. The values refer to the basic profile in accordance with ISO 68-2. 2 Symbols D basic major diameter of internal thread (nominal diameter) d basic major diameter of external thread (nominal diameter) D2 basic pitch diameter of internal thread d2 basic pitch diameter of external thread D1 basic minor diameter of internal thread d1 basic minor diameter of external thread H height of fundamental triangle n number of threads per inch (25,4 mm) BS ISO 725:2009 ISO 725:2009(E) 2 © ISO 2009 – All rights reserved 3 Basic dimensions Dimensions shall be in accordance with Figure 1 and given in Table 1. The values of D2, d2, D1 and d1 have been calculated from the following equations and rounded, in Table 1, to the fourth decimal place: 2 3 0,649 5192 8 D D H D n = − × = − 2 3 0,649 5192 8 d d H d n = − × = − 1 5 1,082 5322 8 D D H D n = − × = − 1 5 1,082 5322 8 d d H d n = − × = − where 0,866 025 40H n= a Pitch, P = 1/n. Figure 1 — Basic dimensions BS ISO 725:2009 ISO 725:2009(E) © ISO 2009 – All rights reserved 3 Table 1 — Basic dimensions Major diameter Number of threads per inch Thread series Pitch diameter Minor diameter D, d n D2, d2 D1, d1 Size in in in No. 0 0,060 0 80 UNF 0,051 9 0,046 5 64 UNC 0,062 9 0,056 1 No. 1 0,073 0 72 UNF 0,064 0 0,058 0 56 UNC 0,074 4 0,066 7 No. 2 0,086 0 64 UNF 0,075 9 0,069 1 48 UNC 0,085 5 0,076 4 No. 3 0,099 0 56 UNF 0,087 4 0,079 7 40 UNC 0,095 8 0,084 9 No. 4 0,112 0 48 UNF 0,098 5 0,089 4 40 UNC 0,108 8 0,097 9 No. 5 0,125 0 44 UNF 0,110 2 0,100 4 32 UNC 0,117 7 0,104 2 No. 6 0,138 0 40 UNF 0,121 8 0,110 9 32 UNC 0,143 7 0,130 2 No. 8 0,164 0 36 UNF 0,146 0 0,133 9 24 UNC 0,162 9 0,144 9 No. 10 0,190 0 32 UNF 0,169 7 0,156 2 24 UNC 0,188 9 0,170 9 28 UNF 0,192 8 0,177 3 No. 12 0,216 0 32 UNEF 0,195 7 0,182 2 20 UNC 0,217 5 0,195 9 28 UNF 0,226 8 0,211 3 1/4 0,250 0 32 UNEF 0,229 7 0,216 2 18 UNC 0,276 4 0,252 4 20 UN 0,280 0 0,258 4 24 UNF 0,285 4 0,267 4 28 UN 0,289 3 0,273 8 5/16 0,312 5 32 UNEF 0,292 2 0,278 7 16 UNC 0,334 4 0,307 3 20 UN 0,342 5 0,320 9 24 UNF 0,347 9 0,329 9 28 UN 0,351 8 0,336 3 3/8 0,375 0 32 UNEF 0,354 7 0,341 2 BS ISO 725:2009 ISO 725:2009(E) 4 © ISO 2009 – All rights reserved Table 1 (continued) Major diameter Number of threads per inch Thread series Pitch diameter Minor diameter D, d n D2, d2 D1, d1 Size in in in 14 UNC 0,391 1 0,360 2 16 UN 0,396 9 0,369 8 20 UNF 0,405 0 0,383 4 28 UNEF 0,414 3 0,398 8 7/16 0,437 5 32 UN 0,417 2 0,403 7 13 UNC 0,450 0 0,416 7 16 UN 0,459 4 0,432 3 20 UNF 0,467 5 0,445 9 28 UNEF 0,476 8 0,461 3 1/2 0,500 0 32 UN 0,479 7 0,466 2 12 UNC 0,508 4 0,472 3 16 UN 0,521 9 0,494 8 18 UNF 0,526 4 0,502 4 20 UN 0,530 0 0,508 4 24 UNEF 0,535 4 0,517 4 28 UN 0,539 3 0,523 8 9/16 0,562 5 32 UN 0,542 2 0,528 7 11 UNC 0,566 0 0,526 6 12 UN 0,570 9 0,534 8 16 UN 0,584 4 0,557 3 18 UNF 0,588 9 0,564 9 20 UN 0,592 5 0,570 9 24 UNEF 0,597 9 0,579 9 28 UN 0,601 8 0,586 3 5/8 0,625 0 32 UN 0,604 7 0,591 2 12 UN 0,633 4 0,597 3 16 UN 0,646 9 0,619 8 20 UN 0,655 0 0,633 4 24 UNEF 0,660 4 0,642 4 28 UN 0,664 3 0,648 8 11/16 0,687 5 32 UN 0,667 2 0,653 7 BS ISO 725:2009 ISO 725:2009(E) © ISO 2009 – All rights reserved 5 Table 1 (continued) Major diameter Number of threads per inch Thread series Pitch diameter Minor diameter D, d n D2, d2 D1, d1 Size in in in 10 UNC 0,685 0 0,641 7 12 UN 0,695 9 0,659 8 16 UNF 0,709 4 0,682 3 20 UNEF 0,717 5 0,695 9 28 UN 0,726 8 0,711 3 3/4 0,750 0 32 UN 0,729 7 0,716 2 12 UN 0,758 4 0,722 3 16 UN 0,771 9 0,744 8 20 UNEF 0,780 0 0,758 4 28 UN 0,789 3 0,773 8 13/16 0,812 5 32 UN 0,792 2 0,778 7 9 UNC 0,802 8 0,754 7 12 UN 0,820 9 0,784 8 14 UNF 0,828 6 0,797 7 16 UN 0,834 4 0,807 3 20 UNEF 0,842 5 0,820 9 28 UN 0,851 8 0,836 3 7/8 0,875 0 32 UN 0,854 7 0,841 2 12 UN 0,883 4 0,847 3 16 UN 0,896 9 0,869 8 20 UNEF 0,905 0 0,883 4 28 UN 0,914 3 0,898 8 15/16 0,937 5 32 UN 0,917 2 0,903 7 8 UNC 0,918 8 0,864 7 12 UNF 0,945 9 0,909 8 16 UN 0,959 4 0,932 3 20 UNEF 0,967 5 0,945 9 28 UN 0,976 8 0,961 3 1 1,000 0 32 UN 0,979 7 0,966 2 8 UN 0,981 3 0,927 2 12 UN 1,008 4 0,972 3 16 UN 1,021 9 0,994 8 18 UNEF 1,026 4 1,002 4 20 UN 1,030 0 1,008 4 1 1/16 1,062 5 28 UN 1,039 3 1,023 8 BS ISO 725:2009 ISO 725:2009(E) 6 © ISO 2009 – All rights reserved Table 1 (continued) Major diameter Number of threads per inch Thread series Pitch diameter Minor diameter D, d n D2, d2 D1, d1 Size in in in 7 UNC 1,032 2 0,970 4 8 UN 1,043 8 0,989 7 12 UNF 1,070 9 1,034 8 16 UN 1,084 4 1,057 3 18 UNEF 1,088 9 1,064 9 20 UN 1,092 5 1,070 9 1 1/8 1,125 0 28 UN 1,101 8 1,086 3 8 UN 1,106 3 1,052 2 12 UN 1,133 4 1,097 3 16 UN 1,146 9 1,119 8 18 UNEF 1,151 4 1,127 4 20 UN 1,155 0 1,133 4 1 3/16 1,187 5 28 UN 1,164 3 1,148 8 7 UNC 1,157 2 1,095 4 8 UN 1,168 8 1,114 7 12 UNF 1,195 9 1,159 8 16 UN 1,209 4 1,182 3 18 UNEF 1,213 9 1,189 9 20 UN 1,217 5 1,195 9 1 1/4 1,250 0 28 UN 1,226 8 1,211 3 8 UN 1,231 3 1,177 2 12 UN 1,258 4 1,222 3 16 UN 1,271 9 1,244 8 18 UNEF 1,276 4 1,252 4 20 UN 1,280 0 1,258 4 1 5/16 1,312 5 28 UN 1,289 3 1,273 8 6 UNC 1,266 7 1,194 6 8 UN 1,293 8 1,239 7 12 UNF 1,320 9 1,284 8 16 UN 1,334 4 1,307 3 18 UNEF 1,338 9 1,314 9 20 UN 1,342 5 1,320 9 1 3/8 1,375 0 28 UN 1,351 8 1,336 3 BS ISO 725:2009 ISO 725:2009(E) © ISO 2009 – All rights reserved 7 Table 1 (continued) Major diameter Number of threads per inch Thread series Pitch diameter Minor diameter D, d n D2, d2 D1, d1 Size in in in 6 UN 1,329 2 1,257 1 8 UN 1,356 3 1,302 2 12 UN 1,383 4 1,347 3 16 UN 1,396 9 1,369 8 18 UNEF 1,401 4 1,377 4 20 UN 1,405 0 1,383 4 1 7/16 1,437 5 28 UN 1,414 3 1,398 8 6 UNC 1,391 7 1,319 6 8 UN 1,418 8 1,364 7 12 UNF 1,445 9 1,409 8 16 UN 1,459 4 1,432 3 18 UNEF 1,463 9 1,439 9 20 UN 1,467 5 1,445 9 1 1/2 1,500 0 28 UN 1,476 8 1,461 3 6 UN 1,454 2 1,382 1 8 UN 1,481 3 1,427 2 12 UN 1,508 4 1,472 3 16 UN 1,521 9 1,494 8 18 UNEF 1,526 4 1,502 4 1 9/16 1,562 5 20 UN 1,530 0 1,508 4 6 UN 1,516 7 1,444 6 8 UN 1,543 8 1,489 7 12 UN 1,570 9 1,534 8 16 UN 1,584 4 1,557 3 18 UNEF 1,588 9 1,564 9 1 5/8 1,625 0 20 UN 1,592 5 1,570 9 6 UN 1,579 2 1,507 1 8 UN 1,606 3 1,552 2 12 UN 1,633 4 1,597 3 16 UN 1,646 9 1,619 8 18 UNEF 1,651 4 1,627 4 1 11/16 1,687 5 20 UN 1,655 0 1,633 4 BS ISO 725:2009 ISO 725:2009(E) 8 © ISO 2009 – All rights reserved Table 1 (continued) Major diameter Number of threads per inch Thread series Pitch diameter Minor diameter D, d n D2, d2 D1, d1 Size in in in 5 UNC 1,620 1 1,533 5 6 UN 1,641 7 1,569 6 8 UN 1,668 8 1,614 7 12 UN 1,695 9 1,659 8 16 UN 1,709 4 1,682 3 1 3/4 1,750 0 20 UN 1,717 5 1,695 9 6 UN 1,704 2 1,632 1 8 UN 1,731 3 1,677 2 12 UN 1,758 4 1,722 3 16 UN 1,771 9 1,744 8 1 13/16 1,812 5 20 UN 1,780 0 1,758 4 6 UN 1,766 7 1,694 6 8 UN 1,793 8 1,739 7 12 UN 1,820 9 1,784 8 16 UN 1,834 4 1,807 3 1 7/8 1,875 0 20 UN 1,842 5 1,820 9 6 UN 1,829 2 1,757 1 8 UN 1,856 3 1,802 2 12 UN 1,883 4 1,847 3 16 UN 1,896 9 1,869 8 1 15/16 1,937 5 20 UN 1,905 0 1,883 4 4 1/2 UNC 1,855 7 1,759 4 6 UN 1,891 7 1,819 6 8 UN 1,918 8 1,864 7 12 UN 1,945 9 1,909 8 16 UN 1,959 4 1,932 3 2 2,000 0 20 UN 1,967 5 1,945 9 6 UN 2,016 7 1,944 6 8 UN 2,043 8 1,989 7 12 UN 2,070 9 2,034 8 16 UN 2,084 4 2,057 3 2 1/8 2,125 0 20 UN 2,092 5 2,070 9 BS ISO 725:2009 ISO 725:2009(E) © ISO 2009 – All rights reserved 9 Table 1 (continued) Major diameter Number of threads per inch Thread series Pitch diameter Minor diameter D, d n D2, d2 D1, d1 Size in in in 4 1/2 UNC 2,105 7 2,0094 6 UN 2,141 7 2,0696 8 UN 2,168 8 2,1147 12 UN 2,195 9 2,1598 16 UN 2,209 4 2,1823 2 1/4 2,250 0 20 UN 2,217 5 2,1959 6 UN 2,266 7 2,1946 8 UN 2,293 8 2,2397 12 UN 2,320 9 2,2848 16 UN 2,334 4 2,3073 2 3/8 2,375 0 20 UN 2,342 5 2,3209 4 UNC 2,337 6 2,229 4 6 UN 2,391 7 2,319 6 8 UN 2,418 8 2,364 7 12 UN 2,445 9 2,409 8 16 UN 2,459 4 2,432 3 2 1/2 2,500 0 20 UN 2,467 5 2,445 9 4 UN 2,462 6 2,354 4 6 UN 2,516 7 2,444 6 8 UN 2,543 8 2,489 7 12 UN 2,570 9 2,534 8 16 UN 2,584 4 2,557 3 2 5/8 2,625 0 20 UN 2,592 5 2,570 9 4 UNC 2,587 6 2,479 4 6 UN 2,641 7 2,569 6 8 UN 2,668 8 2,614 7 12 UN 2,695 9 2,659 8 16 UN 2,709 4 2,682 3 2 3/4 2,750 0 20 UN 2,717 5 2,695 9 4 UN 2,712 6 2,604 4 6 UN 2,766 7 2,694 6 8 UN 2,793 8 2,739 7 12 UN 2,820 9 2,784 8 16 UN 2,834 4 2,807 3 2 7/8 2,875 0 20 UN 2,842 5 2,820 9 BS ISO 725:2009 ISO 725:2009(E) 10 © ISO 2009 – All rights reserved Table 1 (continued) Major diameter Number of threads per inch Thread series Pitch diameter Minor diameter D, d n D2, d2 D1, d1 Size in in in 4 UNC 2,837 6 2,729 4 6 UN 2,891 7 2,819 6 8 UN 2,918 8 2,864 7 12 UN 2,945 9 2,909 8 16 UN 2,959 4 2,932 3 3 3,000 0 20 UN 2,967 5 2,945 9 4 UN 2,962 6 2,854 4 6 UN 3,016 7 2,944 6 8 UN 3,043 8 2,989 7 12 UN 3,070 9 3,034 8 3 1/8 3,125 0 16 UN 3,084 4 3,057 3 4 UNC 3,087 6 2,979 4 6 UN 3,141 7 3,069 6 8 UN 3,168 8 3,114 7 12 UN 3,195 9 3,159 8 3 1/4 3,250 0 16 UN 3,209 4 3,182 3 4 UN 3,212 6 3,104 4 6 UN 3,266 7 3,194 6 8 UN 3,293 8 3,239 7 12 UN 3,320 9 3,284 8 3 3/8 3,375 0 16 UN 3,334 4 3,307 3 4 UNC 3,337 6 3,229 4 6 UN 3,391 7 3,319 6 8 UN 3,418 8 3,364 7 12 UN 3,445 9 3,409 8 3 1/2 3,500 0 16 UN 3,459 4 3,432 3 4 UN 3,462 6 3,354 4 6 UN 3,516 7 3,444 6 8 UN 3,543 8 3,489 7 12 UN 3,570 9 3,534 8 3 5/8 3,625 0 16 UN 3,584 4 3,557 3 4 UNC 3,587 6 3,479 4 6 UN 3,641 7 3,569 6 8 UN 3,668 8 3,614 7 12 UN 3,695 9 3,659 8 3 3/4 3,750 0 16 UN 3,709 4 3,682 3 BS ISO 725:2009 ISO 725:2009(E) © ISO 2009 – All rights reserved 11 Table 1 (continued) Major diameter Number of threads per inch Thread series Pitch diameter Minor diameter D, d n D2, d2 D1, d1 Size in in in 4 UN 3,712 6 3,604 4 6 UN 3,766 7 3,694 6 8 UN 3,793 8 3,739 7 12 UN 3,820 9 3,784 8 3 7/8 3,875 0 16 UN 3,834 4 3,807 3 4 UNC 3,837 6 3,729 4 6 UN 3,891 7 3,819 6 8 UN 3,918 8 3,864 7 12 UN 3,945 9 3,909 8 4 4,000 0 16 UN 3,959 4 3,932 3 4 UN 3,962 6 3,854 4 6 UN 4,016 7 3,944 6 8 UN 4,043 8 3,989 7 12 UN 4,070 9 4,034 8 4 1/8 4,125 0 16 UN 4,084 4 4,057 3 4 UN 4,087 6 3,979 4 6 UN 4,141 7 4,069 6 8 UN 4,168 8 4,114 7 12 UN 4,195 9 4,159 8 4 1/4 4,250 0 16 UN 4,209 4 4,182 3 4 UN 4,212 6 4,104 4 6 UN 4,266 7 4,194 6 8 UN 4,293 8 4,239 7 12 UN 4,320 9 4,284 8 4 3/8 4,375 0 16 UN 4,334 4 4,307 3 4 UN 4,337 6 4,229 4 6 UN 4,391 7 4,319 6 8 UN 4,418 8 4,364 7 12 UN 4,445 9 4,409 8 4 1/2 4,500 0 16 UN 4,459 4 4,432 3 4 UN 4,462 6 4,354 4 6 UN 4,516 7 4,444 6 8 UN 4,543 8 4,489 7 12 UN 4,570 9 4,534 8 4 5/8 4,625 0 16 UN 4,584 4 4,557 3 BS ISO 725:2009 ISO 725:2009(E) 12 © ISO 2009 – All rights reserved Table 1 (continued) Major diameter Number of threads per inch Thread series Pitch diameter Minor diameter D, d n D2, d2 D1, d1 Size in in in 4 UN 4,587 6 4,479 4 6 UN 4,641 7 4,569 6 8 UN 4,668 8 4,614 7 12 UN 4,695 9 4,659 8 4 3/4 4,750 0 16 UN 4,709 4 4,682 3 4 UN 4,712 6 4,604 4 6 UN 4,766 7 4,694 6 8 UN 4,793 8 4,739 7 12 UN 4,820 9 4,784 8 4 7/8 4,875 0 16 UN 4,834 4 4,807 3 4 UN 4,837 6 4,729 4 6 UN 4,891 7 4,819 6 8 UN 4,918 8 4,864 7 12 UN 4,945 9 4,909 8 5 5,000 0 16 UN 4,959 4 4,932 3 4 UN 4,962 6 4,854 4 6 UN 5,016 7 4,944 6 8 UN 5,043 8 4,989 7 12 UN 5,070 9 5,034 8 5 1/8 5,125 0 16 UN 5,084 4 5,057 3 4 UN 5,087 6 4,979 4 6 UN 5,141 7 5,069 6 8 UN 5,168 8 5,114 7 12 UN 5,195 9 5,159 8 5 1/4 5,250 0 16 UN 5,209 4 5,182 3 4 UN 5,212 6 5,104 4 6 UN 5,266 7 5,194 6 8 UN 5,293 8 5,239 7 12 UN 5,320 9 5,284 8 5 3/8 5,375 0 16 UN 5,334 4 5,307 3 4 UN 5,337 6 5,229 4 6 UN 5,391 7 5,319 6 8 UN 5,418 8 5,364 7 12 UN 5,445 9 5,409 8 5 1/2 5,500 0 16 UN 5,459 4 5,432 3 BS ISO 725:2009 ISO 725:2009(E) © ISO 2009 – All rights reserved 13 Table 1 (continued) Major diameter Number of threads per inch Thread series Pitch diameter Minor diameter D, d n D2, d2 D1, d1 Size in in in 4 UN 5,462 6 5,354 4 6 UN 5,516 7 5,444 6 8 UN 5,543 8 5,489 7 12 UN 5,570 9 5,534 8 5 5/8 5,625 0 16 UN 5,584 4 5,557 3 4 UN 5,587 6 5,479 4 6 UN 5,641 7 5,569 6 8 UN 5,668 8 5,614 7 12 UN 5,695 9 5,659 8 5 3/4 5,750 0 16 UN 5,709 4 5,682 3 4 UN 5,712 6 5,604 4 6 UN 5,766 7 5,694 6 8 UN 5,793 8 5,739 7 12 UN 5,820 9 5,784 8 5 7/8 5,875 0 16 UN 5,834 4 5,807 3 4 UN 5,837 6 5,729 4 6 UN 5,891 7 5,819 6 8 UN 5,918 8 5,864 7 12 UN 5,945 9 5,909 8 6 6,000 0 16 UN 5,959 4 5,932 3 BS ISO 725:2009 ISO 725:2009(E) 14 © ISO 2009 – All rights reserved Bibliography [1] ISO 68-2, ISO general-purpose screw threads — Basic profile — Part 2: Inch screw threads [2] ISO 263, ISO inch screw threads — General plan and selection for screws, bolts and nuts — Diameter range 0.06 to 6 in [3] ISO 5408, Screw threads — Vocabulary BS ISO 725:2009 BS ISO 725:2009 ISO 725:2009(E) ICS 21.040.20 Price based on 14 pages © ISO 2009 – All rights reserved BS ISO 725:2009 This page has been intentionally left blank BS ISO 725:2009 BSI Group Headquarters 389 Chiswick High Road, London, W4 4AL, UK Tel +44 (0)20 8996 9001 Fax +44 (0)20 8996 7001 www.bsigroup.com/ standards BSI - British Standards Institution BSI is the independent national body responsible for preparing British Standards. 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