EN 2791:1991

Overview

EN 2791:1991 is a European aerospace standard developed by CEN that specifies dimensions and load requirements for adjustable rod ends used in aircraft systems. These rod ends feature a single fork coupled with a threaded shank designed to achieve engagement of 1.5 times the thread diameter. The standard emphasizes the use of these components primarily in flight control rods and structural rods for aircraft, ensuring reliability and safety in critical aerospace applications. A key characteristic of these rod ends is their cadmium plating, which limits their operational temperature to a maximum of 235°C.

Key Topics

• Adjustable Rod Ends Design
  The standard defines rod ends consisting of a single fork and a threaded shank with specific grooves:

  • A circumferential groove to indicate proper engagement depth.
  • An optional longitudinal groove for locking mechanisms.

• Engagement Specification
  Threaded shank engagement is standardized at 1.5 times the thread diameter, ensuring secure fastening and load distribution.

• Material and Coating
  Cadmium plating is mandated to provide corrosion resistance while emphasizing a temperature limitation of 235°C, which must be considered during component selection and application.

• Dimensional and Load Requirements
  The document outlines precise dimensions and mechanical load capacities essential for safe integration into aerospace systems.

Applications

EN 2791:1991 rod ends are critical components in the aerospace industry, specifically for:

• Flight Control Systems
  They serve as pivotal joints in flight control rods, facilitating adjustable linkages that maintain aircraft maneuverability and safety.

• Aircraft Structural Components
  Used within structural rods where adjustable motion or alignment is necessary, ensuring stability under operational stresses.

• High Performance Aerospace Engineering
  Their thread engagement and locking features support applications subjected to dynamic loads and vibrations.

This standard helps engineers and manufacturers design and validate aerospace-grade adjustable rod ends that meet rigorous safety and performance standards.

Related Standards

• EN 2391 - Covers rod ends with different configurations applicable to aerospace linkage components.
• ISO 12240 - International standard addressing rod end bearings, useful for complementary components.
• MIL-DTL-5541 - U.S. military specification on cadmium plating relevant for corrosion resistance in aerospace fittings.
• AS 5215 - Aerospace standard for rod ends and bearings with additional load and design criteria.

Professionals working in aerospace manufacturing and maintenance can enhance compliance and interoperability by aligning with EN 2791:1991 alongside these related standards.

By adhering to EN 2791:1991, aerospace designers ensure that adjustable rod ends with single forks and robust threaded shanks meet critical dimensional accuracy, load capacity, and temperature resistance requirements, thereby contributing to safer and more reliable aerospace systems.