EN 3911:2010

Aerospace series - Six lobe recess - Geometrical definition

This European Standard specifies the dimensions and tolerances of a six lobe recess.

Luft- und Raumfahrt - Sechs-Bogenzahn, Innenantrieb - Definition der Geometrie

Diese Norm legt die Maße und Grenzmaße des Innenantriebs in Sechs-Bogenzahnausführung fest.

Série aérospatiale - Empreinte six lobes - Définition géometrique

Aeronavtika - Šestzoba vdolbina, notranji pogon - Geometrijske definicije

General Information

• Status: Published
• Publication Date: 19-Oct-2010
• Withdrawal Date: 29-Apr-2011
• ICS: 49.030.01 - Fasteners in general
• Technical Committee: ASD-STAN - Aerospace
• Drafting Committee: ASD-STAN/D 3 - Mechanical
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 20-Oct-2010
• Completion Date: 20-Oct-2010
• Ref Project: SIST EN 3911:2014 - Aerospace series - Six lobe recess - Geometrical definition

Overview

EN 3911:2010 is a European Standard developed by CEN that specifies the dimensions and tolerances of a six lobe recess, widely used in aerospace and defense industries. This standard defines the geometrical characteristics of six lobe recesses to ensure interchangeability, reliability, and precision in the manufacturing of aerospace fasteners and components. The standard provides detailed configurations including measurements, tolerances, and designations to support the consistent production of six lobe drive systems.

Key Topics

• Six Lobe Recess Geometry
  The standard covers the exact geometrical definitions necessary for six lobe recesses. It includes the shape, size, profiles, and critical dimensions essential for ensuring proper fit and torque transmission in aerospace applications.

• Dimensions and Tolerances
  EN 3911:2010 specifies key dimensional parameters, including recess codes corresponding to precise measurements (e.g., diameter, radius, depths) expressed in millimeters. Tight tolerances are defined to meet the high-quality standards required in aerospace fasteners.

• Designation System
  The document introduces a clear designation methodology for identifying different six lobe recess sizes and types by referencing recess codes, facilitating standardized communication in design and manufacturing processes.

• Normative References
  This standard relies on complementary standards such as EN 3905 (technical specifications for six lobe recesses) and NAS 1800 (US aerospace industry reference for recesses), ensuring alignment across international aerospace specifications.

Applications

EN 3911:2010 is primarily intended for use in the aerospace engineering sector, where components must meet stringent safety and performance criteria. Its applications include:

• Aerospace Fasteners Manufacturing
  Ensuring accurate six lobe recess dimensions improves fastener engagement, reduces risks of cam-out, and enhances torque transmission efficiency in aircraft assemblies.

• Component Design and Quality Control
  Engineers and quality inspectors utilize this standard for developing component drawings and carrying out dimensional verifications to maintain conformance with aerospace industry requirements.

• Tooling and Testing
  The standardized dimensions support the design of tooling, gauges, and assembly equipment, enabling manufacturers and maintenance providers to perform consistent installation and maintenance.

• Cross-border Aerospace Projects
  Because EN 3911:2010 is harmonized among European nations and recognized internationally, it aids in collaborative aerospace projects by providing a common technical language for six lobe recess features.

Related Standards

• EN 3905: Aerospace Series - Six Lobe Recesses for Bolts - Technical Specification
  Establishes detailed technical requirements for six lobe recess fasteners complementing EN 3911:2010 geometrical definitions.

• NAS 1800:1990 - Recess, Six Lobe Drive - Internal - Dimensions for Recess and Gages
  A US aerospace standard referenced for dimension derivation and tolerances, ensuring cross-standard compatibility.

• ASD-STAN Standards
  The Aerospace and Defence Industries Association of Europe (ASD-STAN) supports broader aerospace standardization efforts, facilitating integration of EN 3911:2010 with other aerospace fastener standards.

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Keywords: EN 3911:2010, six lobe recess, aerospace fasteners, geometrical definition, CEN standard, aerospace series, six lobe drive, dimensions and tolerances, aerospace manufacturing, aerospace industry standards, ASD-STAN, EN 3905, NAS 1800, aerospace component design, aerospace tooling standards, European aerospace standards.

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Aeronavtika - Šestzoba vdolbina, notranji pogon - Geometrijske definicijeLuft- und Raumfahrt - Verbindungselemente, Innenantrieb - Sechs-BogenzahnSérie aérospatiale - Empreinte six lobes - Définition géometriqueAerospace series - Six lobe recess - Geometrical definition49.030.01Vezni elementi na splošnoFasteners in generalICS:Ta slovenski standard je istoveten z:EN 3911:2010SIST EN 3911:2014en01-marec-2014SIST EN 3911:2014SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 3911
October 2010 ICS 49.030.01 English Version
Aerospace series - Six lobe recess - Geometrical definition
Série aérospatiale - Empreinte six lobes - Définition géometrique
Luft- und Raumfahrt - Sechs-Bogenzahn, Innenantrieb - Definition der Geometrie This European Standard was approved by CEN on 16 April 2010.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 3911:2010: ESIST EN 3911:2014
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