SIST EN 4069:2001

Aerospace series - Nuts, hexagon, plain, reduced height, reduced across flats, in heat resisting steel, passivated - Classification: 600 MPa (at ambient temperature)/650°C

This standard specifies the characteristics of hexagon plain nuts, reduced height, reduced across flats, in heat resisting steel, passivated. Classification: 600 MPa / 650 °C

Luft- und Raumfahrt - Flache Sechskantmuttern, kleine Schlüsselweiten, aus hochwarmfestem Stahl, passiviert - Klasse: 600 MPa (bei Raumtemperatur)/650°C

Diese Norm legt die Eigenschaften von flachen Sechskantmuttern mit kleinen Schlüsselweiten, aus hochwarmfestem Stahl, passiviert, fest. Klasse: 600 MPa / 650 °C

Série aérospatiale - Ecrous hexagonaux ordinaires, hauteur réduite, surplats réduits, en acier résistant a chaud, passivés - Classification: 600 MPa (a température ambiante)/650°C

La présente norme spécifie les caractéristiques des écrous hexagonaux ordinaires, hauteur réduite, surplats réduits, en acier résistant à chaud, passivés. Classification: 600 MPa / 650 °C

Aerospace series - Nuts, hexagon, plain, reduced height, reduced across flats, in heat resisting steel, passivated - Classification: 600 MPa (at ambient temperature)/650°C

General Information

• Status: Published
• Publication Date: 31-Dec-2000
• ICS: 49.030.30 - Nuts
• Technical Committee: SS SPL - Technical Board for the general field
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Jan-2001
• Due Date: 01-Jan-2001
• Completion Date: 01-Jan-2001
• Ref Project: EN 4069:1996 - Aerospace series - Nuts, hexagon, plain, reduced height, reduced across flats, in heat resisting steel, passivated - Classification: 600 MPa (at ambient temperature)/650°C

Overview

EN 4069:1996 (adopted as SIST EN 4069:2001) is a CEN aerospace standard that defines the characteristics of hexagon plain nuts with reduced height and reduced across flats, manufactured from heat resisting steel and passivated. The standard classifies these nuts for a strength level of 600 MPa at ambient temperature and suitability for service up to 650 °C. It is intended for aerospace applications where elevated temperature performance, compact geometry and corrosion protection are required.

Key Topics and Requirements

• Component type and geometry: Specifies the nut form - hexagon plain nuts with reduced height and reduced across flats - optimized for limited space and weight-sensitive assemblies.
• Material: Requires use of heat resisting steel suitable for high-temperature service (classification provided in the scope).
• Strength classification: Defined as 600 MPa (ambient) / 650 °C, indicating the mechanical performance level the nut must meet in normal and high‑temperature conditions.
• Surface treatment: Passivation is required to improve corrosion resistance and compatibility with aerospace environments.
• Characteristics coverage: The standard sets out the essential characteristics manufacturers and purchasers need to ensure interchangeability, quality and safety (dimensions, material designation and performance class are described in the standard text).

(Note: This summary reflects the published scope. Consult the full EN 4069 document for precise dimensional tables, tolerances and acceptance criteria.)

Applications

• Fastening in aero-engine, exhaust and hot-structure assemblies where temperatures approach or reach 650 °C.
• Aircraft systems that require low-profile hex nuts for restricted clearance or to reduce weight.
• Environments where high-temperature mechanical strength and corrosion resistance are critical, such as turbo-machinery and thermal protection components.
• Procurement specifications and quality control for OEMs, suppliers and MRO organizations in the aerospace sector.

Who Uses This Standard

• Aerospace engineers and designers specifying high‑temperature fasteners.
• Fastener manufacturers and heat‑treatment specialists producing certified aerospace hardware.
• Procurement and quality assurance teams validating supplier conformity.
• Maintenance, repair and overhaul (MRO) facilities replacing high‑temperature nuts.

Related Standards

• EN 4069 complements other aerospace fastener standards that cover bolts, washers, thread forms and material heat‑resisting classes. For full system compatibility, consult the relevant EN/Aerospace series documents and the full text of EN 4069 for exact requirements.

Keywords: EN 4069, aerospace nuts, hexagon plain nut, reduced height nut, reduced across flats, heat resisting steel, passivated, 600 MPa, 650 °C.

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Aerospace series - Nuts, hexagon, plain, reduced height, reduced across flats, in heat resisting steel, passivated - Classification: 600 MPa (at ambient temperature)/650°CLuft- und Raumfahrt - Flache Sechskantmuttern, kleine Schlüsselweiten, aus hochwarmfestem Stahl, passiviert - Klasse: 600 MPa (bei Raumtemperatur)/650°CSérie aérospatiale - Ecrous hexagonaux ordinaires, hauteur réduite, surplats réduits, en acier résistan
...