EN 2925:1994

Overview

EN 2925:1994 is a European standard developed by CEN that specifies the characteristics of aerospace-grade bolts with a double hexagon head, relieved shank, and long thread made from heat resisting steel FE-PA92HT (also known as A286). These bolts are classified to withstand a tensile strength of 900 MPa at ambient temperature and maintain performance up to 650 °C. This standard ensures high quality, reliability, and consistency for critical aerospace fasteners used in demanding environments involving elevated temperatures and mechanical stress.

Key Topics

• Bolt Type: Double hexagon head bolts with relieved shank and long thread, designed for aerospace applications.
• Material Specification: Heat resisting steel FE-PA92HT (A286), known for its exceptional strength and corrosion resistance at elevated temperatures.
• Strength Classification: Bolts classified to 900 MPa tensile strength at ambient temperature, with capability to operate reliably up to 650 °C.
• Dimensional and Mechanical Requirements: Precise definitions on dimensions, thread length, and mechanical properties to meet aerospace safety and performance standards.
• Temperature Resilience: Special consideration for performance at high temperatures, critical for aerospace engine and structural applications.
• Quality Assurance: Emphasis on strict manufacturing and testing protocols to guarantee consistency and reliability in critical aerospace environments.

Applications

EN 2925 bolts are specifically engineered for aerospace industry uses where mechanical strength, high temperature resistance, and durability are essential. Typical applications include:

• Aircraft Engines: Fastening components within jet engines where exposure to extreme heat is common.
• Airframe Structures: Securing load-bearing structures that require high tensile strength and resistance to thermal stress.
• Aerospace Assemblies: Used in various aerospace assemblies where bolt performance at elevated temperatures and under mechanical load is critical.
• High-performance Aerospace Components: Components subject to cyclic stress and hot operating environments, benefiting from the relieved shank design to reduce stress concentration.

Related Standards

For broader compliance and integration within the aerospace industry, EN 2925 is often referenced alongside other standards covering aerospace fasteners and materials:

• EN 24374 - Aerospace fasteners - bolts, screws, and studs made of corrosion-resistant steels.
• EN 28754 - Aerospace series - nuts with hexagon, castle, and other heads.
• EN 29001 / ISO 9001 - Quality management systems in aerospace manufacturing.
• ASTM A286 - American standard for heat-resistant stainless steel alloys, same material as FE-PA92HT.
• NASM 25027 - Aerospace standard for high temperature, corrosion-resistant bolts.

Using EN 2925:1994 ensures that aerospace bolts meet essential performance criteria, providing designers and manufacturers confidence in the mechanical integrity and heat resistance of critical fasteners. This contributes directly to flight safety, reliability, and operational efficiency in aerospace technology.