SIST EN 3709:2009

Aerospace series - Wrenches and sockets, bi-hexagonal - Technical specification

This standard specifies the requirements to be complied with by wrenches and double-hex sockets intended for aerospace products.

Luft- und Raumfahrt - Ringschlüssel und Steckschlüsseleinsätze, Doppelsechskant - Technische Lieferbedingungen

Diese Norm legt die Anforderungen an Ringschlüssel und Steckschlüsseleinsätze mit Doppelsechskant für die Anwendung in der Luft- und Raumfahrt fest.

Série aérospatiale - Clé et douille bihexagonale - Spécification technique

Aeronavtika - Vijačniki (obročni in nasadni), biheksagonalni - Tehnična specifikacija

General Information

• Status: Published
• Publication Date: 25-May-2009
• ICS: 49.030.99 - Other fasteners
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 16-Apr-2009
• Due Date: 21-Jun-2009
• Completion Date: 26-May-2009
• Ref Project: EN 3709:2006 - Aerospace series - Wrenches and sockets, bi-hexagonal - Technical specification

Overview

EN 3709:2006 - Aerospace series - Wrenches and sockets, bi‑hexagonal - Technical specification is a CEN / AECMA-STAN European standard that defines the technical and quality requirements for bi‑hexagonal (double‑hex) wrenches and sockets used in aerospace products. The standard covers material and surface requirements, dimensional and geometric tolerances, mechanical performance under torsional loading, test methods, qualification and production acceptance, plus marking and packaging expectations.

Key topics and requirements

• Scope: Applies to wrenches and double‑hex sockets intended for aerospace applications.
• Materials & surface: Materials must meet product‑standard property requirements; surfaces shall be free from pits, cracks, forging burrs and other defects. Acceptable finishes include polished, brushed or satin with uniform bright or dull appearance.
• Inner tooth profile: Tooth top, flank and bearing faces must be burr‑free and provide optimum load bearing.
• Mechanical tests: Integrity and endurance are verified by torsional testing. Key test parameters include:
  • Endurance torques and integrity torques are size‑specific (tables provide values for common metric sizes - e.g., 6 mm wrench: endurance 20 Nm, integrity 30 Nm; up to 22 mm: endurance 400 Nm, integrity 800 Nm).
  • Endurance cycles: 1 000 cycles in both directions, maximum cadence 60 per minute.
  • Integrity check: 1.5× endurance torque applied every 250th cycle.
• Test fixtures: Wrenches are tested on a hexagonal mandrel machined to ISO 4095 dimensions, tolerance h8, minimum hardness 55 HRC. Socket insertion depth and square drive mandrel specifications are defined for consistent testing.
• Qualification & acceptance: Qualification tests required per type/size combination; production acceptance sampling plans and AQL (e.g., AQL 2.5% table for visual/dimensional inspections) and destructive sampling rules are specified.
• Marking & packaging: Marking follows product standard; packaging left to manufacturer option.

Applications and who uses it

EN 3709 is intended for:

• Aerospace OEMs and component manufacturers specifying tooling for assembly
• MRO (maintenance, repair, overhaul) organizations and aircraft maintenance engineers
• Tooling suppliers and special fastener/tool manufacturers
• Procurement and quality assurance teams defining acceptance criteria and inspection plans

Practical benefits include improved tool interchangeability, predictable torque transmission, reduced fastener damage, and documented qualification/acceptance procedures for safety‑critical aerospace assemblies.

Related standards

• ISO 1174 - Assembly tools for screws and nuts - Driving squares
• ISO 4095 - Aerospace - Bihexagonal drives - Wrenching configuration - Metric series
• EN 9133 - Aerospace series - Quality management systems - Qualification procedure for aerospace standard parts

Keywords: EN 3709, bi‑hexagonal wrenches and sockets, aerospace tools, torque testing, qualification and acceptance, aircraft maintenance, tooling standards.

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.KQLþQDVSHFLILNDFLMDLuft- und Raumfahrt - Ringschlüssel und Steckschlüsseleinsätze, Doppelsechskant - Technische LieferbedingungenSérie aérospatiale - Clé et douille bihexagonale - Spécification techniqueAerospace series - Wrenches and sockets, bi-hexagonal - Technical specification49.030.99Drugi vezni elementiOther fastenersICS:Ta slovenski standard je istoveten z:EN 3709:2006SIST EN 3709:2009en,de01-julij-2009SIST EN 3709:2009SLOVENSKI
STANDARD
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 3709April 2006ICS 49.030.99 English VersionAerospace series - Wrenches and sockets, bi-hexagonal -Technical specificationSérie aérospatiale - Clé et douille bihexagonale -Spécification techniqueLuft- und Raumfahrt - Ringschlüssel undSteckschlüsseleinsätze, Doppelsechskant - TechnischeLieferbedingungenThis European Standard was approved by CEN on 3 February 2006.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, 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 STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2006 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 3709:2006: ESIST EN 3709:2009

Assembly tools for screws and nuts — Driving squares. ISO 4095,
Aerospace — Bihexagonal drives — Wrenching configuration — Metric series. EN 9133,
Aerospace series — Quality management systems — Qualification procedure for aerospace standard parts. 3 Terms and definitions For the purposes of this standard, the following terms and definitions apply. 3.1 lot a lot is composed of wrenches or sockets of the same type, originating from the same material defined by the same standard 4 Requirements 4.1 Materials The materials shall meet the required properties specified in the product standard. 4.2 Physical properties 4.2.1 Surface condition and appearance The wrenches and sockets shall be free from pits, deposits, forging burrs, cracks, splits, flashes and other defects likely to modify their properties and endurance or to injure users. The wrench handle shall allow an easy handling and its shape shall permit a correct guiding of the box end. The wrenches and the outer surface of the sockets shall have a polished, brushed or s
...