Tiêu chuẩn iso 15872 2017

INTERNATIONAL STANDARD ISO 15872 Second edition 2017-03 Aerospace — UNJ threads — Gauging Aéronautique et espace — Filetage UNJ — Vérification par calibres Reference number ISO 15872:2017(E) © ISO 2017 ISO 15872:2017(E) COPYRIGHT PROTECTED DOCUMENT © ISO 2017, Published in Switzerland All rights reserved Unless otherwise specified, no part o f this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission Permission can be requested from either ISO at the address below or ISO’s member body in the country o f the requester ISO copyright o ffice Ch de Blandonnet • CP 401 CH-1214 Vernier, Geneva, Switzerland Tel +41 22 749 01 11 Fax +41 22 749 09 47 copyright@iso.org www.iso.org ii © ISO 2017 – All rights reserved ISO 15872:2017(E) Page Contents Foreword iv Scope Normative references Terms, definitions, symbols and abbreviated terms Types o f gauges 4.1 Gauges and setting plugs for external threaded products 4.2 Gauges for internal threaded products Reference temperature Function, design and use of gauges 6.1 Gauges for external threads 6.1.1 Virtual pitch diameter indicating thread gauges 6.1.2 Solid or adjustable GO screw ring gauges 6.1.3 Simple pitch diameter indicating thread gauges 6.1.4 Major diameter gauges 6.1.5 Minor diameter gauges 6.1.6 Optical comparator checks 6.2 Gauging for internal threads 6.2.1 GO screw plug gauges 6.2.2 NOT GO screw plug gauges 6.2.3 Minor diameter gauges 6.2.4 Virtual pitch diameter indicating thread gauges 6.2.5 Simple pitch diameter indicating thread gauges Setting of gauges 7.1 Setting gauges for external threads 7.2 Setting ring gauge for indication thread gauges Gauging of threads 8.1 General 8.2 Internal threads evaluation Bibliography 22 Terms and definitio ns Symb o ls and ab b reviated terms © ISO 2017 – All rights reserved iii ISO 15872:2017(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies) The work o f 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 o f electrotechnical standardization The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part In particular the different approval criteria needed for the di fferent types o f ISO documents should be noted This document was dra fted in accordance with the editorial rules of the ISO/IEC Directives, Part (see www.iso org/directives) Attention is drawn to the possibility that some o f the elements o f this document may be the subject o f patent rights ISO shall not be held responsible for identi fying any or all such patent rights Details o f any patent rights identified during the development o f the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso org/patents) Any trade name used in this document is in formation given for the convenience o f users and does not constitute an endorsement For an explanation on the voluntary nature o f standards, the meaning o f ISO specific terms and expressions related to formity assessment, as well as in formation about ISO’s adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso org/iso/foreword html This document was prepared by ISO/TC 20, Aircraft and space vehicles, Subcommittee SC 4, Aerospace fastener systems This second edition cancels and replaces the first edition (ISO 15872:2002), which has been technically revised and includes the following changes: — unused symbols have beenremoved from Table 1: WGO, WNG, Z1, ZPL, and ZR — Terminology has been updated — The document has been editorially revised — — iv Figures have been changed to align with 8.1 Normative references have been updated © ISO 2017 – All rights reserved INTERNATIONAL STANDARD ISO 15872:2017(E) Aerospace — UNJ threads — Gauging Scope This document provides methods for the gauging o f ISO UNJ threads complying with ISO 3161 Other methods o f ensuring that the product is within the specified limits can be used, provided that correlation with the specified gauges is established Normative references The following documents are re ferred to in the text in such a way that some or all o f their content constitutes requirements o f this document For dated re ferences, only the edition cited applies For undated re ferences, the latest edition o f the re ferenced document (including any amendments) applies ISO 1, Geometrical product specifications (GPS) — Standard reference temperature for the specification of geometrical and dimensional properties ISO 3161, Aerospace — UNJ threads — General requirements and limit dimensions Terms, definitions, symbols and abbreviated terms 3.1 Terms and definitions For the purposes o f this document, the terms and definitions given in ISO 5408 and the following apply ISO and IEC maintain terminological databases for use in standardization at the following addresses: — IEC Electropedia: available at http://www.electropedia org/ — ISO Online browsing platform: available at http://www.iso org/obp 3.1.1 best wire size cylinder or sphere which has a radius so that it will contact the thread flanks at the pitch cylinder intersection Note to entry: The radius o f the best wire or sphere is theoretically equal to 0,288 68 P 3.1.2 indicating gauge device having contacts which will precisely compare the size o f a work piece thread to a setting standard of known dimensions Note to entry: The value for the indicated characteristic thus established is the dimensional value attributed to the work piece An indicating gauge can have contacts designed to measure any thread characteristic This document specifies the characteristics and designs for ISO UNJ threads 3.1.3 simple pitch diameter diameter o f an imaginary cylinder intersecting an actual thread over the width o f one groove where that width is equal to one half of the basic pitch © ISO 2017 – All rights reserved ISO 15872:2017(E) 3.1.4 virtual pitch diameter pitch diameter of the smallest (for external threads) or largest (for internal threads) perfect thread f f thread engagement orm with G O gauge pro fi le wh ich c a n engage the pro duc t th re ad s or a d i s tance e qua l to the G O gauge 3.2 Symbols and abbreviated terms See Table Table — Symbols, abbreviated terms and definitions Symbol or abbreviated term D1 d2 es EI H H1 HP (LSL) m (USL) P Definition Basic minor diameter of the internal thread of a workpiece Basic pitch diameter of the external thread of a workpiece Fundamental deviation of the external thread of a workpiece Fundamental deviation of the internal thread of a workpiece Height of the triangle of a thread pro fi le Tolerance for the diameter of plain plug gauges Tolerance on the size of check plug gauges for plain calliper gauges L ower s p e c i fic atio n l i m it Distance between the middle of the tolerance zones TR of a screw ring gauge and TCP of a GO check plug Upp er s p e c i fic atio n l i m it Pitch Symbol or abbreviated term Definition Tα1 /2 To lera nce Tα2 /2 To lera nce TCP Td Td2 Td3 TD1 TP TD2 TPL TR fo r e ach fl a n k a ngle o f a p ro fi le with comple te fl a n ks fo r e ach fl a n k a ngle o f a p ro fi le with tr u nc ate d fl a n ks Tolerance on the pitch diameter of GO and NOT GO screw check plugs, wear check plugs and setting plugs Tolerance for the major diameter of the external thread of a workpiece Tolerance for the pitch diameter of the external thread of a workpiece Tolerance for the minor diameter of the external thread of a workpiece Tolerance for the minor diameter of the internal thread of a workpiece Pitch tolerance Tolerance for the pitch diameter of the internal thread of a workpiece Tolerance for the pitch diameter of GO and NOT GO screw plug gauges Tolerance for the pitch diameter of GO and NOT GO screw ring gauges © ISO 2017 – All rights reserved ISO 15872:2017(E) 4 T y p G a e u s g o e f s g a a n u d g s e e s t t i n g p l u g s f o r e x t e r n a l t h r e a d e d p r o d u c t s The function, design and use of gauges and setting plugs for external threads are explained in the following subclauses G a) b) c) d) e) f) g) a u g e t y p e S u GO screw ring gauges Setting plug for adjustable GO screw ring and indicating thread gauges Virtual pitch diameter indicating thread gauges Simple pitch diameter indicating thread gauges Flat contact gauges for major diameter Point contact indicating thread gauges for minor diameter Optical comparator for root radius and minor diameter G a u g e s f o r i n t e r n a l t h r e a d e d p r o d u c b c l a u s e 6.1.2 7.1.1 6.1.1 6.1.3 6.1.4 6.1.5 6.1.6 t s The function, design and use of gauges for internal threads are explained in the following subclauses G a u g e t y p e a) b) c) d) e) f) GO screw plug gauges NOT GO screw plug gauges Plain gauges for minor diameter (plug gauge) GO full form screw plug gauges Virtual pitch diameter indicating thread gauges Simple pitch diameter indicating thread gauges g) S e tti ng ri ng gauge for i nd ic ati ng th re ad gauge s (s ol id typ e) S u b c l a u s e 6.2.1 6.2.2 6.2.3.1 6.2.3.2 6.2.4 6.2.5 7.2 Reference temperature In accordance with ISO 1, the dimensions of the gauge and the product shall be checked at the temperature of 20 °C I f the pro duc t a nd the gauge have the s ame co e fficients o f l i ne a r exp a n s ion, the temp eratu re may deviate from 20 °C, provided the temperature of the product and the gauge are the same I f the pro duc t a nd the gauge h ave d i fferent co e fficients o f l i ne ar exp an s ion, the temp eratu re o f b o th, at the time of gauging, shall be: a) 20 °C ± °C for sizes 1,000 UNJ and smaller; b) 20 °C ± °C for larger threads © ISO 2017 – All rights reserved ISO 15872:2017(E) Function, design and use of gauges 6.1 Gauges for external threads 6.1.1 Virtual pitch diameter indicating thread gauges It measures, on two or three segments or rolls, the maximum material virtual pitch diameter f taper which produces an enlargement of the virtual pitch diameter In addition, virtual pitch diameter f maximum limit Measurement of virtual pitch diameter with indicating gauges shall be obtained to calculate virtual minus simple pitch diameter differential unless the simple pitch diameter limits, gauged f in accordance with 6.1.3 variation limits in ISO 3161 6.1.1.1 taking into acco unt variatio ns o f o rm s uch as p itch variatio n, helix and flank variatio ns , ro undnes s and co ntro l ens ures the flank angle co ntact is s u ficient to ens ure that the ro o t radius es no t exceed the , are within the limits defined by the maximum p itch diameter and the 6.1.1.2 I ndicating gauges have two or three co ntacts at 80° or °, res p ectively Gauges o rm with segments or rolls are designed with the length of the GO virtual maximum material gauging elements equal to the GO ring gauge length equal to nine pitches (P) or the basic major diameter of the thread, Figure whichever is the s malles t Fo r co nfiguratio n and p ro file requirements , s ee The minor diameter of the GO virtual maximum material thread segments and the diameter of diameter of the product minus 0,375 H, less the TPL value in Table minus tolerance when assembled in f f P on the minor crest for the thread The crest 6.1.1.3 the circle s urro unded by the ro ll clus ter o f GO virtual maximum material ro lls s hall b e equal to the p itch the gauge rame This co rres p o nds to a flat width o ,3 s hall b e flat in an axial p lane and p arallel to the axis o f the s egments o r ro lls 6.1.1.4 The major diameter of the GO virtual maximum material segments and the root of the GO virtual maximum material ro lls s hall b e cleared b eyo nd a , P flat either by an extens io n o f the flanks o f the P maximum width and ap p roximately thread to ward a s harp vee o r by an undercut no greater than , central The root clearance shall be such that the major diameter of the full form section of the thread s etting p lug gauge is cleared a fter the as s emb led gauge has b een p ro p erly s et to s ize 6.1.1.5 The p itch diameter cylinder axis o f threaded s egments and ro lls s hall b e s traight within the diameter tolerance zone equal to TPL thread s hall b e within the limits s p ecified in 6.1.2 Table The half-angle variations in the segment or roll Table For the pitch variations, see Table s p ecified in Solid or adjustable GO screw ring gauges To en s u re the e as e o f a s s embly o f pro duc t th re ad s and formance to the ma xi mum materia l vi r tua l pitch diameter limits, solid or adjustable, GO screw ring gauges with thread form in accordance with Figure and setting gauges in accordance with 7.1.1 not be permitted to exceed the product thread dimensional limits The gauge thickness/length shall be standardized (see 6.1.1.2 be obtained from ASME B1.2 may b e u s e d S ol id G O s c rew ri ng gauge s s l l ) D e ta i l s on adj u s table G O th re ad ri ng gauge s and tru nc ate d s e tti ng plugs may 6.1.3 Simple pitch diameter indicating thread gauges The simple pitch diameter indicating gauge with cone and vee rolls or segments or rolls with best wire size radius is applied to ensure that the pitch diameter is greater than the minimum limit The indicators are set to the GO threaded setting plug gauge Readings indicate the position of the pitch diameter and the minimum measurement shall be no less than the minimum pitch diameter limit The minimum measured pitch diameter shall be within the ISO 3161 form variation limit compared to the virtual pitch diameter measurement in accordance with 6.1.1, i.e the differential value The simple pitch diameter contacts have cone and vee rolls or segments which contact the product pitch c yl i nder O ther de s ign s h ave two or th re e rol l s with rad i i on a n nu lar rib s on rol l s made to b e s t © ISO 2017 – All rights reserved ISO 15872:2017(E) wire size The product thread contacts are restricted to 1,5 pitch lengths See Figure and Figure for design and contact form M a j o r d i a m e t e r g a u g e s The maximum limit o f the major diameter may be checked with a plain ring gauge, a plain GO calliper, or plain diameter-measuring device; see Figure The minimum limit of the major diameter shall be checked with a plain diameter measuring device set to a plain diameter plug with HP tolerance (see Table ) A plain micrometer calliper may be used to measure the major diameter and may have standard gauge block settings 6.1.5 Minor diameter gauges It shall be set to the plain minor diameter setting plug with HP tolerance (see Table 5) See Figure for design and contact form O p t i c a l c o m p a r a t o r c h e c k s The optical comparator shall be used to veri fy the root radius by comparing the shadow contour to the radius charts The minor diameter may also be measured with an optical comparator using appropriate measuring techniques 6 2 G a u G g O i n s c g f o r e w r p i l n u t e g r n g a a u l g e t h r e a d s s To ensure the ease o f assembly o f threads and formance to the maximum material virtual pitch and major diameter limits, GO screw plug gauges or the full form GO screw plug gauge in accordance with 6.2.3.2 shall be used For gauge tolerances, see Table to Table N O T G O s c r e w p l u g g a u g e s To check that the simple pitch diameter is not greater than the maximum limit, NOT GO screw plug gauges shall be used For gauge tolerances, see Table to Table 6.2.3 Minor diameter gauges 6.2.3.1 The minimum minor diameter may be evaluated by a plain cylindrical GO plug gauge or a GO full form screw plug gauge in accordance with 6.2.3.2 The maximum minor diameter may be checked with a plain cylindrical NOT GO plug gauge The diameters o f the plain plugs shall be based on the minimum minor diameter specified in ISO 3161 with gauge tolerance H1 specified in Table Internal micrometer callipers may be used to measure the minor diameter 6.2.3.2 The GO full form screw plug gauge shall be a modified GO screw plug gauge with a controlled root radius on the gauge (see Figure ) equal to the maximum external thread root radius specified in ISO 3161 with a radius tolerance in accordance with Table V i r t u a l p i t c h d i a m e t e r i n d i c a t i n g t h r e a d g a u g e s It measures, on two or three segments or rolls, the maximum material virtual pitch diameter and taper which produces a decrease in the virtual pitch diameter The virtual pitch diameter shall be measured using indicating gauges to calculate the simple minus virtual pitch diameter differential unless the simple pitch diameter limits are within the limits defined by the minimum pitch diameter and the form variation limits in ISO 3161 6.2.4.1 taking into account variations o f form such as pitch variation, helix and flank variations, roundness © ISO 2017 – All rights reserved ISO 15872:2017(E) Indicating gauges have two or three contacts at 180° or 120°, respectively Gauges with 6.2.4.2 segments or rolls are designed with the length of the GO virtual maximum material gauging elements equal to the GO plug gauge length equal to nine pitches (P) or the basic major diameter of the thread, whichever is the smallest For configuration and profile requirements, see Figure S i m p l e p i t c h d i a m e t e r i n d i c a t i n g t h r e a d g a u g e s The simple pitch diameter indicating thread gauge with cone and vee rolls or segments or rolls with the best wire size radius is applied to ensure that the pitch diameter is not greater than the maximum limit The indicators are set to the GO threaded ring gauge Readings indicate the position of the pitch diameter and the maximum measurement shall be not greater than the maximum pitch diameter limit The maximum measured pitch diameter shall be within the ISO 3161 form variation limit compared to the virtual pitch diameter measurement made in accordance with 6.2.4.1 The simple pitch diameter contacts have cone and vee rolls or segments which contact the product pitch cylinder Other designs have two or three rolls with radii on annular ribs on rolls made to best wire size The product thread contacts are restricted to 1,5 pitch lengths See Figure and Figure for design and contact form for simple pitch diameter indicating thread gauges Setting of gauges S e t t i n g g a u g e s f o r e x t e r n a l t h r e a d s The virtual pitch diameter indicating gauge is set to the threaded setting plug whose average simple pitch diameter (see Figure 10) is equal to basic size Set and check the GO screw ring gauge as required Check the GO screw plug gauge as required 7.1.1 Set the simple pitch diameter indicating gauge to the calibrated or marked pitch diameter setting plug gauge These gauges are the same setting gauges as described in 7.1 to permit differential measurement calculations 7.1.2 Set the major and minor diameter indicating gauges to their respective plain setting plugs The diameter of these plain setting plugs shall be made to the maximum dimension with a negative tolerance of HP (see Table 6, Figure 11 and Figure 12 ) The micrometer callipers may have standard gauge block settings 7.1.3 7.2 Setting ring gauge for indication thread gauges The virtual pitch diameter indicating thread gauge and the simple pitch diameter indicating thread gauge to measure internal threads is set with the solid GO screw ring gauge Gauging of threads G e n e r a l Gauges with a wear allowance, which allows gauges to exceed the maximum or minimum limits of the product thread, are not permitted for UNJ threads A product thread characteristic is acceptable when any appropriate standardized gauge can be assembled The manu facturer is responsible for ensuring that, whatever the case, the means ultimately ensures characteristics in accordance with the envelope requirements External threads shall be evaluated as follows a) Check the virtual pitch diameter by measurement using either an indicating gauge or an assembly with a GO threaded ring gauge © ISO 2017 – All rights reserved ISO 15872:2017(E) T a 10 over — 0.002 0.003 0.005 0.008 0.012 0.020 See Figure 10 a b l e — Td2 F a c t o r m for setting gauges up to and including 0.002 0.003 0.005 0.008 0.012 0.020 0.026 Values in inches ma 0.004 0.005 0.006 0.007 0.008 0.010 0.013 © ISO 2017 – All rights reserved ISO 15872:2017(E) Segments two or three contacts a Z e r o l e a d r o l l s two or three contacts pitch diameter f maximum major diameter of product external thread form of segment or roll gauge thread form maximum minor diameter of product external thread clear 0,125 P when not undercut 10 maximum pitch diameter of product external thread f f f 11 central when undercut maximum product external thread a The total segment contact to be a minimum of 25 % of circumference K e y o r two o r three co ntacts res p ectively o rm o F i relie g u r e o p tio nal — width ap p roximately — V i r t u © ISO 2017 – All rights reserved a l p i t c h d i a m e t e r i p itch cylinder n d i c a t i n g t h r e a d g a u g e s f o r e x t e r n a l threads 11 ISO 15872:2017(E) Segments two or three contacts a Z e r o l e a d r o l l s two or three contacts pitch diameter form of relief optional gauging element external thread a The total segment contact to be a minimum of 25 % of circumference b Contact central on pitch line K e F i y g 12 u r e — S i m p l e p i t c h d i a m e t e r i n d i c a t i n g t h r e a d g a u g e s w i t h c o n e a n d v e e f o r e x t e r n a l threads © ISO 2017 – All rights reserved ISO 15872:2017(E) Rolls three or two contacts Key pitch diameter roll external thread a Rolls — Gauging contacts b Best wire size radius c Two ribs on top roll d One rib on bottom roll e One rib on each roll, one-third pitch apart Figure — Simple pitch diameter indicating thread gauges with radius roll for external threads © ISO 2017 – All rights reserved 13 ISO 15872:2017(E) Segments two or three contacts R o l l s two or three contacts major diameter plain gauge contact external thread K e y F 14 i g u r e — M a j o r d i a m e t e r i n d i c a t i n g p l a i n g a u g e s f o r e x t e r n a l threads © ISO 2017 – All rights reserved ISO 15872:2017(E) Segments two or three contacts three thread segments or rolls radius not to exceed root radius of part external thread K e y Z e r l e a d r o l l s f minor diameter o r two o r three co ntacts res p ectively Figure — Minor diameter indicating thread gauges for © ISO 2017 – All rights reserved o two or three contacts e x t e r n a l threads 15 ISO 15872:2017(E) major diameter pitch diameter minor diameter K e y F 16 i g u r e — G O f u l l f o r m s c r e w p l u g g a u g e s f o r m a x i m u m m a t e r i a l , i n t e r n a l threads © ISO 2017 – All rights reserved ISO 15872:2017(E) GO threaded segments two or three contacts a K e y Threaded contacts pitch diameter minimum major diameter of product internal thread minimum product internal thread gauge thread form clear 0,125 P when undercut fo rm G O z e r o l e a d r o l l s two or three contacts o f relie f o p tio nal — width ap p roximately central when undercut minimum minor diameter of product internal thread minimum pitch diameter of product internal thread 10 a The total segment contact to be a minimum of 25 % of circumference p itch cylinder fingers F i g u r e — V i r t u © ISO 2017 – All rights reserved a l p i t c h d i a m e t e r i n d i c a t i n g t h r e a d g a u g e s f o r i n t e r n a l threads 17 ISO 15872:2017(E) C o n t a c t s a b o v e p i t c h l i n e a C o n Segments two or three contacts b pitch diameter K e y t a c t s c e n t r R a o l l l o s n p i t c h l i n e a two or three contacts internal thread gauging elements form of relief optional a Alternate designs: Contacts in other positions near the pitch cylinder may also be applied b The total segment contact to be 25 % or more of circumference F i g 18 u r e — S i m p l e p i t c h d i a m e t e r i n d i c a t i n g t h r e a d g a u g e s w i t h c o n e a n d v e e f o r i n t e r n a l threads © ISO 2017 – All rights reserved ISO 15872:2017(E) T h r e e r o l l t y p e : o n e r i b o n e a c h r o l l , o n e t h i r d T w o r o pitch apart B a l l d e s i g l l o t t y h p e e r : r t w o o l l , r o i n n b e s - o h R o l n a l l s o f n p i e t r c o h l l a , p o a n r e r i b o n t two or three contacts pitch diameter internal thread gauging contacts with best size thread balls a Best wire size radius = 0,288 68 P K e gauging contacts with one-half best size thread wire diameter form of relief optional y flo ating — s p aced three p itches ap art F i g u r e — S i m p l e p i t c h © ISO 2017 – All rights reserved d i a m e t e r i n d i c a t i n g t h r e a d g a u g e s w i t h r a d i u s r o l l f o r i n t e r n a l threads 19 ISO 15872:2017(E) GO NOT GO maximum limit, max d2 a See 7.1.1 b See Table K e F i average simple pitch diameter gauge pitch diameter lower limit, d2 y g u r e — T o l e r a n c e z o n e f o r t h e p i t c h d i a m e GO NOT GO maximum limit, max d2 a See 6.1.4 K e F i 20 u r e 1 — T o l e r a n c e z e r o f G O t h r e a d s e t t i n g p l u g g a u g e s f o r e x t e r n a l setting plug gauge lower limit, d2 y g t threads and gauge setting o n e f o r s e t t i n g p l a i n p l u g g a u g e s f o r m a j o r d i a m e t e r o f e x t e r n a l threads © ISO 2017 – All rights reserved ISO 15872:2017(E) Key GO NOT GO maximum limit, max d3 a setting plug gauge lower limit, d3 a See 6.1.5 Figure 12 — Tolerance zone for setting plain plug gauges for minor diameter o f external threads a) External threads b) Internal threads Key 30° ± Tα1 f 30° ± Tα2 f clearing diameter pitch diameter major diameter minor diameter a /2 o r p ro file with co mp lete flanks /2 o r p ro file with truncated flanks Thes e diameters no t exis t o n anvils for GO (comp lete flanks) N OT GO (truncated flanks ) s crew calliper gauges Figure 13 — Hal f-angle profile © ISO 2017 – All rights reserved 21 ISO 872 : 01 7(E) Bibliography [1] [2] [3] [4] [5] ISO 5408, Screw threads — Vocabulary ISO 8015, Geometrical product specifications (GPS) — Fundamentals — Concepts, principles and rules ISO 14253-1, Geometrical product specifications (GPS) — Inspection by measurement ofworkpieces and measuring equipment — Part 1: Decision rules for proving formity or noncon formity with specifications ISO 14638, Geometrical product specifications (GPS) — Matrix model ASME B1.2, Gages and Gaging for Unified Screw Threads1) 1) ASME International, 345 East 47 th Street, New York, NY 10017-2392, USA 22 © ISO 2017 – All rights reserved ISO 872 : 01 7(E) ICS  49.030.10 Price based on 22 pages © ISO 2017 – All rights reserved