ISO INTERNATIONAL STANDARD 228-2 Second edition 1987-08-15 INTERNATIONALORGANIZATIONFOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION MEXKAYHAPOAHAAOPIAHM3ALMHO CTAHAAPTW3ALMM Pipe threads where pressure-tight joints are not made on the threads Part 2 : Verification by means of limit gauges Filetages de tuyauterie pour raccordement sans étancheite dans le filet - Partie2:Verificationparcalibresalimites Reference number ISO 228-2: 1987 (E) 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 bodyinterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhas the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with Iso, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by international Standard iSO 228-2 was prepared by Technical Committee ISO/TC 5, Ferrous metal pipes and metallic fittings. This second edition cancels and replaces the first edition (IS0 228-2 : 1980), of which it constitutesaminorrevision. Usersshouldnotethatall International Standardsundergorevisionfromtimetotime and that any reference made herein to any other International Standard implies its latestedition,unlessotherwisestated ? International Organization for Standardization, 1987 Printed in Switzerland CopyrightIntematinal Organizatin for Standardizatin gpermitted without licensefromIHS Not for Resale ISO 228-2 : 1987 (E) INTERNATIONAL STANDARD Pipe threads where pressure-tight joints are not made on the threads - Part 2 : Verification by means of limit gauges 1 Scope and field of application Table 1 This part of Iso 228 specifies the verification, by means of limit Symbol Explanation igauges, of cylindrical threads, the dimensions and tolerances b3 Width of clearance groove at the major and minor of which are given in ISo 228-1. diameter respectively of the thread profile with trun- cated flanks For industrial applications (see for example Iso 1179), it may be d=D Basic major diameter of the thread 'necessary to carry out additional checks. d = Dt d. 1,280 654 P : Basic minor diameter of the thread Since this 55° profile has different elements to be verified, it is necessary to provide for several GO and several NOT GO d2= D2 : d - 0,640 327 P : Basic pitch diameter of the thread gauges : m Distancebetween the middle of the tolerance zones a) the threaded GO gauges (see clauses 6 and 7) shall en- Tr of the threaded ring gauge and Tcp of the GO sure that the profile of the machined piece does not exceed check plug the maximum of material provided for by the tolerances ap- n Nominal value of b3 plied to the dimensions of the profile defined by ISo 228-1; p Pitch Displacement of the clearance groove with trun- b) the threaded NOT GO gauges for the threads of the cated flanks pieces (see clauses 6 and 7) fix the minimum material limit on the flanks of the thread. s Tolerance on b3 Tcp Tolerance on the pitch diameter of GO and NOT GO NOTE Reference checks may be carried out in specialized threaded check plugs and wear check plugs laboratories. Td2 Tolerance on the pitch diameter of the external thread TD2 Tolerance on the pitch diameter of the internal thread 2 References TpL Tolerance on the pitch diameter of GO and NOT GO threaded plug gauges Iso 228-1,Pipe threads where pressure-tight joints are not TR Tolerance on the pitch diameter of GO and NOT GO made on the threads - Part 1 : Designation, dimensions and threaded ring gauges tolerances. u 0,147 84 P : Twice the radial height of rounding ISO 1179, Pipe connections, threaded to /SO 228-1, for plain at crestand root of thread end steel and other metal tubes in industrial