EN 4307:2005

Overview

EN 4307:2005 is a European standard developed by CEN that specifies the technical requirements for tubular sleeves designed for shear screws with flush heads. These sleeves are manufactured from corrosion-resisting steel with passivation treatment and have a precise wall thickness of 0.50 mm. The standard is part of the aerospace series and ensures the sleeves meet stringent criteria for dimensions, material properties, surface treatment, and durability at operating temperatures up to 650 °C.

This standard is critical for aerospace manufacturers and suppliers seeking to maintain quality and safety in structural fasteners used in aviation and aerospace applications. It establishes consistent specifications to facilitate interchangeability, performance reliability, and compliance with industry-wide quality demands.

Key Topics

• Material Specifications
  The sleeves are made from corrosion-resistant steel conforming to EN 2175, enhanced by passivation according to EN 2516 for surface protection and longevity in harsh aerospace environments.

• Dimensions and Configurations
  Detailed dimensional criteria, including diameters, lengths, groove patterns (plain or annular grooves), and tolerances, are outlined to ensure precision. Sleeve wall thickness is fixed at 0.50 mm, supporting structural integrity for shear screw applications.

• Maximum Operating Temperature
  These sleeves are designed to operate reliably at temperatures up to 650 °C, meeting the thermal requirements often found in aerospace conditions.

• Manufacturing Process
  Sleeves are produced by drawing sheet or strip stock into seamless tubular forms, assuring high structural continuity without defects such as cracks, seams, or laps.

• Surface Quality Requirements
  The standard prohibits material flaws and allows minor surface characteristics like continuous axial flow lines or an orange peel effect, common to drawing processes but benign for aerospace use.

• Marking and Identification
  Marking follows EN 2424 standards to ensure traceability, facilitating quality control and inventory management within aerospace supply chains.

• Sampling and Inspection
  Quality inspections comply with ISO 2859-1, implementing acceptance quality limits (AQL) at 1% to ensure consistent manufacturing standards via appropriate sampling plans.

Applications

• Aerospace Fastening Systems
  EN 4307 sleeves are used extensively in aerospace structural assemblies, particularly for shear screws requiring flush-headed sleeves that resist corrosion and thermal stress.

• Aircraft Manufacturing and Maintenance
  The standard supports manufacturers and maintenance providers in selecting sleeves that meet strict safety and performance standards, enabling high reliability and safety in aircraft operations.

• High-Temperature Aerospace Components
  Given the 650 °C temperature rating, these sleeves are suitable for use near engines, exhaust systems, or other locations with elevated thermal environments.

• Standardization for Aerospace Suppliers
  Suppliers of aerospace components rely on EN 4307:2005 to harmonize product specifications, enabling compatibility and quality assurance across international aerospace manufacturing networks.

Related Standards

• EN 2175 – Aerospace series standard for heat-resisting alloy steel used in the sleeves, specifying mechanical properties and heat treatment.
• EN 2516 – Passivation requirements for corrosion-resistant steels and nickel alloys, ensuring enhanced surface protection for aerospace components.
• EN 2424 – Aerospace product marking, providing guidance for traceability and identification codes used on components.
• ISO 2859-1 – Sampling procedures for attribute inspection, defining methods for acceptance quality limits during production quality control.

Keywords: EN 4307:2005, aerospace sleeves, tubular sleeves, shear screws, corrosion resisting steel, passivated steel, aerospace fasteners, flush head screws, tubular sleeve dimensions, aerospace standards, high-temperature aerospace components, aerospace manufacturing, aerospace quality control, EN 2175, EN 2516, ISO 2859-1.