EN 3760:1996

Overview

EN 3760:1996 is a CEN aerospace standard that defines the characteristics of a specific type of high-performance screw: 100° countersunk normal head, offset cruciform recess, threaded to head, manufactured from heat and corrosion resisting steel and passivated. The document specifies mechanical classification as 1 100 MPa (at ambient temperature)/425 °C, making it suitable for aerospace applications requiring both high strength and elevated-temperature resistance.

Key topics and requirements

• Head form and geometry
  • 100° countersunk normal head for flush mounting in structural assemblies.
  • Offset cruciform recess (specialized Phillips-type recess) for drive engagement.
• Threading
  • Threaded to head (thread extends close to the head) to maximize grip length in short or thin components.
• Material and treatment
  • Heat and corrosion resisting steel to maintain mechanical properties at elevated temperatures.
  • Passivated surface condition to reduce corrosion risk and improve longevity.
• Mechanical classification
  • Specified as 1 100 MPa (at ambient temperature)/425 °C, indicating rated strength and elevated-temperature capability as defined in the standard text.
• Quality and conformity
  • Requirements typically cover dimensional tolerances, material verification, mechanical testing, and surface treatment acceptance criteria (refer to the full standard for test methods and inspection limits).

Applications

• Aerospace structural and engine assemblies where a flush, high-strength fastener is required.
• Components exposed to elevated temperatures (up to the classification limit) and corrosive environments, such as engine compartments, hot-air ducts, and external airframe attachments.
• Use cases include new aircraft design, refurbishment, maintenance/repair operations, and supply chain procurement where compliance with aerospace fastener standards is mandated.

Who uses EN 3760

• Aerospace design engineers specifying fasteners for high-temperature, corrosion-prone applications.
• Fastener manufacturers producing certified aerospace screws.
• Quality assurance and procurement teams verifying compliance for flight-critical components.
• Maintenance, repair, and overhaul (MRO) organizations applying correct replacements during service.

Related standards

• EN 3760 should be used alongside other aerospace and fastener standards (e.g., general fastener dimension and testing standards) to ensure full compliance across design, testing, and procurement processes.

Keywords: EN 3760, aerospace screws, 100° countersunk, offset cruciform recess, threaded to head, heat and corrosion resisting steel, passivated, high-temperature fasteners, aerospace fasteners, 1 100 MPa/425 °C.