ISO 2790:2020

Overview

ISO 2790:2020 - "Belt drives - V‑belts for the automotive industry and corresponding pulleys - Dimensions" establishes dimensional and designation requirements for V‑belts and matching pulleys used to drive auxiliaries on internal combustion engines in the automotive sector. The fifth edition updates geometry and adds cogged (notched) belt types, providing clear rules for cross‑sections, groove profiles, measurement methods and tolerances to ensure interchangeability and reliable accessory drives.

Key topics and technical requirements

• Belt profiles and types: Standardizes three AV cross‑sections - AV 10, AV 13, AV 17 - and distinguishes plain and cogged (X) belt variants.
• Cross‑section dimensions: Specifies nominal top widths and belt angles for each profile and notes possible customer‑manufacturer agreement on angle changes.
• Groove geometry for pulleys: Defines groove angle (36° ± 0.5°), effective groove widths (e.g., 9.7, 12.7, 16.8 mm for AV 10/13/17), minimum groove depths and corner radii, plus corrective terms used in effective diameter calculations.
• Measurement and checking: Describes the standardized method to measure effective belt length and ride‑out, the use of checking pulleys (effective diameter example ~95.49 mm), and the procedure to check pulley effective diameter using balls/rods.
• Tolerances and uniformity: Provides centre‑distance variation limits by belt length (e.g., ≤1.2 mm up to 1 000 mm; ≤1.6 mm for 1 000–2 000 mm; ≤2.0 mm over 2 000 mm) and run‑out measurement methods.
• Designation rules: Specifies naming conventions for belts (e.g., AV 10X – 1200) and pulleys (e.g., 67 x 1 AV 10), supporting unambiguous ordering and documentation.

Applications and who uses it

ISO 2790:2020 is used by:

• Automotive OEMs and Tier suppliers to specify belts and pulley geometry for accessory drives (alternators, water pumps, A/C compressors, power steering).
• Belt and pulley manufacturers for production and quality control to ensure parts meet standard dimensions and interoperate across suppliers.
• Testing laboratories and QA teams to perform standardized dimensional checks and conformity tests.
• Maintenance and repair organizations to identify correct replacement belts and pulleys using standardized designations.

Practical benefits include improved interchangeability, predictable belt seating and tension behavior, and reduced assembly and service issues.

Related standards

• ISO 1081 (vocabulary for V‑belts and pulleys)
• ISO 9608 (centre distance variation test methods)
• ISO 8370‑1 (pitch zone location testing for V‑belts)

Keywords: ISO 2790:2020, V‑belts, automotive pulleys, AV 10, AV 13, AV 17, cogged belts, belt dimensions, pulley dimensions, belt designation, centre distance variation.