Overview
ISO 3584:2020 - Road vehicles - Clevis couplings - Interchangeability defines the mounting and interchangeability characteristics for clevis couplings on towing-vehicle frames (cross member, drawbeam or mounting bracket) used to connect trailers fitted with a drawbar eye. The standard ensures dimensional compatibility, required clearances, articulation ranges and load-test references so that couplings and frames from different manufacturers can mate reliably.
Key topics and technical requirements
- Scope and identification
- Applies to clevis couplings for trailers with a drawbar eye; unspecified characteristics remain at the manufacturer’s discretion.
- Frames and couplings are identified by reference to ISO 3584 plus a category or class (e.g., “Clevis coupling ISO 3584 C 40 - Category 3”).
- Mounting categories and drilling patterns
- Defines categories of drilling patterns and corresponding mounting dimensions for frame attachment (Tables and figures provide E, D, drilling tolerances).
- Specifies minimum flat surface areas (dimensions F, G, L, T) required on the frame for secure mounting.
- Dimensional envelope and operating clearance
- All coupling components must fit within an envelope box (Table 3 / Figure 3) and provide safe clearances for actuating devices.
- Articulation angles
- Couplings must permit non-simultaneous articulation of: ±90° horizontal, ±20° vertical and ±25° axial rotation to accommodate vehicle/trailer movement.
- Load and performance
- Couplings must satisfy strength tests in ISO 8718 and/or ISO 12357.
- Classified C 40 and C 50 couplings have defined characteristic values (D, S, static loads) - for example C40 classes include D-values such as 18, 25, 70, 100, 130 kN; C50 classes extend to higher values (up to 190 kN).
- C 40 / C 50 compatibility
- C 40 is intended for 40 mm drawbar eyes (ISO 8755); C 50 for 50 mm drawbar eyes (ISO 1102). Classified dimensions and tests are provided.
Applications and users
- Vehicle OEMs and chassis/frame designers specifying mounting interfaces for towing vehicles.
- Trailer and coupling manufacturers designing interchangeable clevis couplings (C 40 / C 50).
- Test laboratories performing strength and conformity tests per referenced standards.
- Fleet operators, regulators and maintenance engineers seeking compatibility, safety and retrofit guidance for towing systems.
- Procurement teams ensuring parts interchangeability across suppliers.
Related standards
- ISO 8755 - 40 mm drawbar eye - Interchangeability
- ISO 1102 - 50 mm drawbar eye - Interchangeability
- ISO 8718 - Drawbar couplings and eyes - Strength tests
- ISO 12357 - Drawbar couplings and eyes for rigid drawbars
- ISO 11406 / ISO 11407 - Coupling clearance guidance and interchangeability for towing vehicles
Keywords: ISO 3584, clevis couplings, interchangeability, drawbar eye, towing vehicles, trailer coupling, mounting categories, articulation angles, C40, C50.
