EN 2139:1989

Overview

EN 2139:1989 is a European standard established by CEN that defines the specifications for flat heat resisting steel washers used in aerospace applications. These washers are specifically designed to maintain integrity and performance at temperatures up to 650 °C. Primarily, the washers serve as reliable components beneath nuts in high-temperature environments common to aerospace engineering. When used under bolt heads, compatibility with the assembly must be verified to ensure safety and functionality.

This standard supports the aerospace industry's demand for durable fasteners and related components that withstand elevated temperatures while preventing loosening and mechanical failure. By adhering to EN 2139, manufacturers and engineers ensure consistent quality and performance of flat washers critical to the safety and longevity of aerospace structures.

Key Topics

• Material Requirements
  EN 2139 specifies the type of heat resisting steel suitable for flat washers capable of enduring temperatures below 650 °C without compromising mechanical properties.

• Dimensional Characteristics
  The standard outlines precise dimensions and tolerances for flat washers to guarantee compatibility with nuts and bolts used in aerospace assemblies.

• Application Guidelines
  Washers are primarily designated for placement beneath nuts. When applied under bolt heads, users must verify compatibility to maintain mechanical integrity.

• Temperature Resistance
  Focused on elevated temperature performance, the washers must sustain structural stability, corrosion resistance, and dimensional accuracy within the defined thermal limits.

• Quality and Compliance
  EN 2139 ensures that washers meet strict aerospace quality standards, supporting reliable fastening solutions under demanding temperature conditions.

Applications

Flat heat resisting steel washers complying with EN 2139 are extensively used in aerospace engineering fields such as:

• Aircraft Engines
  Supporting fasteners in engine components exposed to high heat, ensuring secure assemblies under thermal stress.

• Airframe Structures
  Used in critical joints where heat resistance and mechanical strength are essential for safety and performance.

• Exhaust and Turbine Assemblies
  Providing thermal endurance in fastening elements exposed to exhaust gases and turbine heat.

• Spacecraft Components
  Reliable fastening solutions in spacecraft requiring materials that perform under fluctuating temperature extremes.

By standardizing these washers, EN 2139 facilitates uniform manufacturing quality, simplifying procurement and ensuring interchangeability across aerospace equipment.

Related Standards

• EN 1661:1986 – Aerospace series - Nuts in heat resisting steel for use at elevated temperatures, complementing EN 2139 washers for high-temperature fastening assemblies.

• EN 28717:2001 – Aerospace series - Bolts, studs, and screws in heat resisting steel, often used in conjunction with EN 2139 washers.

• ISO 4759-1 – Tolerances for fasteners, which includes guidelines applicable to washers' dimensional and form tolerances.

• ASTM F436 – Standard specification for hardened steel washers, providing alternative material specifications for engineering applications.

Understanding these related standards helps aerospace engineers design and maintain high-performance fastener systems combining heat resistance and mechanical reliability.

Keywords: EN 2139, aerospace washers, heat resisting steel washers, flat washers, elevated temperature fasteners, aerospace fastening standards, high temperature washers, CEN aerospace standards, washers for nuts, aerospace hardware.