EN 2680:2006

Overview

EN 2680:2006 is a European aerospace standard that specifies the characteristics of self-locking, floating, self-aligning, two lug anchor nuts made of alloy steel. These nuts feature cadmium plating and molybdenum disulphide (MoS2) lubrication, designed for metric series applications. Classified for a tensile strength of 900 MPa at ambient temperature and capable of enduring temperatures up to 235 °C, this standard ensures high-performance fastening components suitable for demanding aerospace environments.

Developed by the European Association of Aerospace Manufacturers (AECMA) and adopted by CEN, EN 2680 ensures consistent quality, reliability, and interoperability of critical aerospace fasteners. The nuts covered by this standard withstand mechanical stresses while maintaining locking integrity, even under thermal exposure consistent with aviation requirements.

Key Features

• Self-locking and self-aligning: Enables secure fastening with tolerance for alignment variations, improving joint reliability.
• Floating two lug design: Allows for angular adjustment to compensate for misalignments during assembly.
• Alloy steel construction: Offers high strength and durability, supporting a classification tensile strength of 900 MPa at room temperature.
• Cadmium plating: Provides corrosion resistance and ensures longevity of the nut in harsh aerospace operating conditions.
• Molybdenum disulphide (MoS2) lubrication: Reduces friction for optimal performance under torque during installation.
• Metric thread series: Conforms to aerospace metric threading standards outlined in ISO 12273.

Applications

EN 2680 anchor nuts are primarily used in aerospace manufacturing and maintenance, contributing to the safety and structural integrity of aircraft. Their features make them ideal for:

• Aircraft assembly: Providing reliable fastening for structural components where precise torque and alignment are essential.
• Maintenance and repair: Facilitating replacement and servicing of components requiring dependable locking nuts under variable stress and temperature conditions.
• Aerospace equipment manufacturing: Ensuring consistency and compatibility in high-strength fastening solutions within aerospace systems.
• High-temperature environments: Withstanding exposure up to 235 °C without compromising mechanical properties, suitable for engine compartments and other thermal zones.

Related Standards

EN 2680 interfaces with several other key aerospace standards that govern thread dimensions, quality management, coatings, and material properties:

• ISO 12273: Defines dimensional requirements and classifications for two lug anchor nuts with metric threads.
• ISO 5858: Procurement specifications for aerospace self-locking nuts operating below 425 °C.
• EN 2133: Specifies requirements for cadmium plating on aerospace-grade steels.
• EN 2491: Details the coating methods for MoS2 dry lubricants applied to aerospace fasteners.
• EN 9100 & EN 9133: Standards for aerospace quality management systems and qualification procedures for aerospace standard parts.
• TR 3791: Technical report specifying materials for self-locking nuts and inserts with temperature classifications up to 425 °C.

Practical Value

Compliance with EN 2680:2006 guarantees that anchor nuts utilized in aerospace applications meet stringent performance, durability, and safety criteria. The standardized classification at 900 MPa tensile strength and cadmium plated MoS2 lubrication allows engineers and manufacturers to select fasteners optimized for high-stress environments and temperature endurance. Adoption of this standard supports interoperability across international aerospace supply chains and helps maintain rigorous quality assurance through defined testing and manufacturer approval processes.

Keywords: EN 2680, aerospace nuts, self-locking nuts, floating two lug nuts, alloy steel nuts, cadmium plated nuts, MoS2 lubricated nuts, aerospace fasteners, high strength nuts, metric aerospace nuts, anchor nuts standard, aerospace hardware, high temperature nuts, aerospace manufacturing standards.