ISO 2790:2020

INTERNATIONAL ISO
STANDARD 2790
Fifth edition
2020-06
Belt drives — V-belts for the
automotive industry and
corresponding pulleys — Dimensions
Transmissions par courroies — Courroies trapézoïdales pour la
construction automobile et poulies correspondantes — Dimensions
Reference number
©
ISO 2020
© ISO 2020
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ii © ISO 2020 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Belts . 1
4.1 General . 1
4.2 Cross-section . 2
4.3 Measurement of the effective length of a belt and its ride-out . 3
4.4 Centre distance variations . 4
5 Service pulleys . 5
5.1 General . 5
5.2 Dimensions . 5
5.3 Checking of effective diameter . 7
5.4 Designation . 8
Bibliography . 9
Foreword
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iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 41, Pulleys and belts (including veebelts),
Subcommittee SC 1, Friction.
This fifth edition cancels and replaces the fourth edition (ISO 2790:2004), which has been technically
revised. The main changes compared to the previous edition are as follows:
— the cogged type has been added throughout the document;
— the symmetry of the groove has been changed from (90 ± 2)° to (90 ± 0,5)° in Table 4, as in ISO 9981;
— the designation of belt has been added.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved

INTERNATIONAL STANDARD ISO 2790:2020(E)
Belt drives — V-belts for the automotive industry and
corresponding pulleys — Dimensions
1 Scope
This document specifies the requirements for belts and pulleys for V-belt drives used for driving
auxiliaries of internal combustion engines for the automotive industry.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 1081, Belt drives — V-belts and V-ribbed belts, and corresponding grooved pulleys — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1081 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Belts
4.1 General
A belt is defined by its cross-section, type and by its effective length in millimetres measured under
specified conditions. Cogged belt is represented by X.
Belt types are given in Figure 1.
a) Raw-edge plain be
...