ISO 1081:2013

Overview

ISO 1081:2013 - Belt drives: V-belts and V-ribbed belts, and corresponding grooved pulleys - Vocabulary defines the standardized terms, definitions and symbols (in English and French) used for V-belt drives, V-belts, hexagonal and joined V‑belts, V-ribbed belts and their corresponding grooved pulleys. The standard clarifies how geometric features such as pitch width, top width, height, pitch diameter and groove geometry are described, and establishes two independent systems for groove and belt dimensions: the datum-width system and the effective-width system.

Key Topics

• Vocabulary for belt types: definitions for V-belt, hexagonal belt, joined V-belt, V-ribbed belt, pitch line and pitch zone.
• Pulley terminology: V-grooved pulley, groove angle, pitch width of pulley groove, pitch diameter, effective diameter, datum diameter, groove bottom and transitional radii.
• Two measurement systems:
  • Datum-width-based system: terms such as datum width, datum diameter, datum length and datum line differential.
  • Effective-width-based system: terms such as effective width, effective diameter, effective length and effective line differential.
• Drive and performance terms: V-belt drive, speed ratio (based on pitch diameters without slip/creep allowances), tension, modulus-related vocabulary and measurement guidelines.
• Measurement conventions: recommended methods for measuring datum/effective lengths using measuring fixtures and pulleys of defined diameters; use of pitch lines and pitch zones for consistent length and width measurement.
• Bilingual presentation: definitions provided in both English and French to support international use.

Applications

ISO 1081:2013 is a foundational reference for anyone working with belt drives where consistent terminology is critical:

• Design engineers specifying belt/pulley geometry in power transmission systems.
• Manufacturers producing V-belts, V-ribbed belts and grooved pulleys to ensure consistent dimensioning and interoperability.
• Maintenance teams diagnosing belt fit, wear and replacement using standardized terms (pitch width, effective length, elongation).
• Quality and testing labs performing length, tension and dimensional checks using the datum/effective measurement systems.
• Procurement and technical writers creating specifications, datasheets and installation manuals that require unambiguous vocabulary.

Who uses this standard

• Mechanical and power-transmission engineers
• Belt and pulley manufacturers and suppliers
• Maintenance and reliability professionals
• Standards committees and educators

Related Standards

ISO 1081:2013 was prepared by ISO/TC 41 (Pulleys and belts). It complements other ISO standards and technical documents that govern belt drive design, testing and safety; users should consult the relevant ISO technical committee outputs for design or test specifications.