ISO NTERNATIONAL STANDARD 522 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION ·MEK IYHAPOIHA OPTAHM3ALIM IO CTAHIAPTW3ALIWM·ORGANISATION INTERNATIONALE DE NORMALISATION Special tolerances for reamers Tolerances speciales d'alésoirs First edition -- 1975-02-15 052:2-1975(E) UDC 621.951.7 : 621.753.1 Ref.No. ISO 522-1975 (E) Descriptors : tools, reamers, dimensions, dimensional tolerances. Price hased on 2 pages FOREWORD iso (the internationai Organization for Standardization) is a woridwide federation of national standards institutes (Iso MemberE Bodies). The work of developing Internationa! Standards is carried out through !So Technica! Committees. Every Member Body interested in a subject for which a Technical Committee has been set up 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. Draft International Standards adopted by the Technical Committees are circulated to the Member Bodies for approval before their acceptance as International Standards by the isO Council. Prior to 1972, the resuits of the work of the Technicai Committees were pubished as Iso Recommendations;these documents are now in theprocess of being transformed into International Standards. As part of this process, Technical technically suitable for transformation. International Standard ISO 522 therefore replaces ISO Recommendation R 522-1966 to which it is technically identical. countries : Australia France Poland Austria Germany Portuga! Belgium Hungary Spain Brazil India Sweden Canada Italy Switzerland Chile ueder UnitedKingdom Coiombia Korea, Rep. of U.S.S.R. Czechoslovakia Netherlands Yugoslavia Denmark New Zealand The Member Bodyof the following country expressed disapproval of the Recommendation on technical grounds : U.S.A. The Member Body of the following country disapproved the transformation of ISO/R 522 into an International Standard : Sweden International Organization for Standardization, 1975 Printed in Switzeriand INTERNATIONAL STANDARD ISO522-1975(E) Special tolerances for reamers 1 SCOPEANDFIELDOFAPPLICATION The value 0,15 IT should be rounded upwards to a whole multiple of 0,001 mm (or 0.000 1 in). This International Standard specifies the special tolerances to be applied to the diameter of the cutting portion of the the low limit of the diameter of the reamer is equal hand and machine reamers covered by iSO/R 236, Hand to its maximum diameter, minus 0,35 IT. reamers and long fluted machine reamers, Morse taper shank, and iSO/R521,Machine chucking reamers with The value 0,35IT should be rounded upwards to a parallel shanks or Morse taper shanks, when a grade of whole multiple of 0,001 mm (or 0.000 1 in). accuracy other than the standard stock grade (with m6 NOTE - For inch size reamers, the IT values are obtained by direct tolerance) provided for in these ISo Recommendations is conversion from the metric IT values. required. Tolerances on the hole 2 DETERMINATIONOFTOLERANCES on the reamer Unless otherwise specified in the order, reamers are made to the tolerance m6 (standard stock grade) and it is impossible to infer in advance what tolerances can be guaranteed on theholesproduced withthesetools. The actual diameter of a hole produced by a given reamer Maximum diameter of the hole. depends in practice on very many factors. These factors diameter of reame include : a) the type of material to be cut and the amount of diameter of reamer material to be removed; Low limit of the b) the cutting angle of the reamer; of the hole c) the condition of the reamer at the time of use; d) the method of mounting and operation; e) the lubrication. These different factors should be taken into account when determining the special tolerances tobe called for on a 2.2 General remark reamer for the production of a hole with a given tolerance. It is thus impossible to establish, for this type It is always possibie to make reamers with greater precision