ISO 3

INTERNATIONAL STANDARD INTERNATIONAL ORGANIZATION

Preferred numbers

 DE

Series of preferred numbers

First edition

3:44 pm, 6/21/06 

UDC 389.171

Ref. No.

  3-1973

  preferred numbers.

Price based on 4 pages

FOREWORD   (the International Organization for Standardization) is a worldwide federation of national standards institutes  Member Bodies). The work of developing International Standards is carried out through   Technical 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  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   Council. Prior to 1972, the results of the work of the Technical Committees were published as  Recommendations; these documents are now in the process of being transformed into International Standards. As part of this process, International Standard  3 replaces  Recommendation R 3-1954 drawn up by Technical Committee  19, Preferred numb ers. The Member Bodies of the following countries approved the Recommendation Australia Austria Belgium Chile Denmark Finland France Germany Hungary

 

 

India Israel Italy Mexico Netherlands New Zealand Norway Portugal South Africa, Rep. of 

Spain Sweden Switzerland United Kingdom U.S.A. U.S.S.R.  Yugoslavia

No Member Body expressed disapproval of the Recommendation.

International Organization for Standardization,

Printed

in Switzerland

l

  3-1973

INTERNATIONAL STANDARD

Preferred numbers

Series of preferred numbers

1 SCOPE AND FIELD OF APPLICATION This International Standard specifies series of preferred numbers.

1

and the derived series is designated by

4.6.2 In general, if  is the index of the basic series

 5, 10, 20 or 40,

 is the pitch of the derived series, i.e. the number of  steps in the basic series required to build up the &rived series, the ratio of the derived series is

On the other hand, if N is a positive integral number, the term of identification of the derived series is

Lastly, if   is any integral number, positive, zero or  negative, any term of the derived series is