SIST EN 4609:2020

Aerospace series - Spiral drive recesses for threaded fasteners - Geometrical definition and technical requirements

This European Standard specifies dimensions, tolerances, characteristics and qualification requirements for MORTORQ Spiral Drive Recesses .
[MORTORQ® is the trade name of a product supplied by licensees of the Phillips Screw Company. This information is given for the convenience of users of this European Standard and does not constitute an endorsement by ASD-STAN nor CEN of the product named. Equivalent products may be used if they can be shown to lead to the same results.]

Luft- und Raumfahrt - Spiral-Innenantrieb für Schrauben - Definition der Geometrie und Technische Anforderungen

Diese Europäische Norm gibt die Maße, Grenzabmaße, Eigenschaften und Qualifizierungsanforderungen für MORTORQ Spiralinnenantriebe an.
[MORTORQ® ist das Warenzeichen eines Produkts, geliefert von Lizenznehmern der Phillips Screw Company. Diese Angabe dient zur Orientierung der Anwender dieser Europäischen Norm und stellt keine Empfehlung des genannten Produkts durch ASD-STAN oder CEN dar. Gleichwertige Produkte dürfen verwendet werden, wenn sie nachweisbar zu identischen Ergebnissen führen.]

Série aérospatiale - Empreintes spiral pour vis - Définition géométrique et exigence technique

Le présent document spécifie les dimensions, tolérances, caractéristiques et exigences de qualification pour les empreintes en spirale MORTORQ.
[MORTORQ® est le nom commercial d'un produit fourni par les licenciés de la Phillips Screw Company. Ces informations sont fournies pour la commodité des utilisateurs de la présente Norme européenne et ne constituent pas une approbation du produit mentionné par l'ASD-STAN ou le CEN. Des produits équivalents peuvent être utilisés s'ils démontrent qu'ils conduisent aux mêmes résultats.]

Aeronavtika - Spiralni pogoni za navojne pritrdilne elemente - Geometrijska opredelitev in tehnične zahteve

Ta dokument določa dimenzije, odstopanja in kvalifikacijske zahteve za MORTORQ Spiral Drive Recesses1.

General Information

• Status: Published
• Publication Date: 21-Nov-2019
• ICS: 49.030.01 - Fasteners in general
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 20-Nov-2019
• Due Date: 25-Jan-2020
• Completion Date: 22-Nov-2019
• Ref Project: EN 4609:2019 - Aerospace series - Spiral drive recesses for threaded fasteners - Geometrical definition and technical requirements

Overview

EN 4609:2019 (CEN) specifies the geometrical definition, dimensions, tolerances, characteristics and qualification requirements for MORTORQ® spiral drive recesses used in aerospace threaded fasteners. The standard covers recess form, nominal and root diameters for drive sizes MT-000 through MT-7, inspection gauges, test apparatus and detailed torque/verification procedures. Note: MORTORQ is a trade name licensed by the Phillips Screw Company; equivalent drive systems may be used if they produce the same results. A patent claim (EP1025370B1) is noted in the document.

Keywords: EN 4609:2019, spiral drive recesses, MORTORQ, aerospace fasteners, drive recess dimensions, tolerances, recess gauging, torque testing.

Key Topics

• Scope: Defines dimensions, tolerances and qualification requirements for MORTORQ spiral drive recesses in aerospace applications.
• Geometry & Dimensions: Recess form illustrated (Figure 1). Key dimensions include recess diameter (øD) and root diameter (øE) for drive sizes MT-000 to MT-7 (values listed in Table 1).
• Penetration depth: Specified per fastener part standard; measurement guidance is provided using the defined gauges.
• Recess gauging: Two acceptance inspection gauge types:
  • GO / NO-GO hand plug gauges (Figure 2, Table 2) for entry checks.
  • Dial penetration gauge (Figures 4–5, Table 3) for measuring recess penetration compared to flat steel reference.
• Test apparatus & fixtures: Requirements to constrain bit alignment (bit axis within 1° of fastener axis), prevent fastener rotation, apply specified end load and torque without resisting cam-out.
• Test procedure & torque verification: Stepwise method to measure flatness, apply end load (default 90 ±1 N if unspecified), apply installation/removal torque and record results. Representative wrench torque values are provided (Table 4) - e.g., typical values range from fractions of a Nm for very small diameters up to several hundred Nm (up to ~790 Nm for MT-7) depending on fastener size and design.
• Driver bit: Shall be appropriate to the recess and conform to applicable industry or manufacturer standards.

Applications

• Design, production and qualification of aerospace fasteners using spiral drive recesses.
• Quality control and inspection: Acceptance gauging and torque verification in manufacturing and maintenance.
• Procurement and specification: OEMs and suppliers can reference EN 4609:2019 to ensure interchangeability and inspection criteria.
• Users: fastener manufacturers, aerospace OEMs, design engineers, test labs, maintenance organizations and quality/acceptance inspectors.

Related Standards

• ISO 128 (technical drawings)
• ISO 1101 (geometrical tolerancing)
• Applicable military, industry or manufacturer driver-bit standards referenced for driver geometry and tooling.

This standard is essential when specifying or inspecting spiral drive recess fasteners in aerospace contexts to ensure consistent geometry, reliable torque capacity and clear acceptance criteria.

Standards Content (Sample)

SLOVENSKI STANDARD
01-januar-2020
Aeronavtika - Spiralni pogoni za navojne pritrdilne elemente - Geometrijska
opredelitev in tehnične zahteve
Aerospace series - Spiral drive recesses for threaded fasteners - Geometrical definition
and technical requirements
Luft- und Raumfahrt - Spiral-Innenantrieb für Schrauben - Definition der Geometrie und
Technische Anforderungen
Série aérospatiale - Empreintes spiral pour vis - Définition géométrique et exigence
technique
Ta slovenski standard je istoveten z: EN 4609:2019
ICS:
49.030.01 Vezni elementi na splošno Fasteners in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 4609
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2019
EUROPÄISCHE NORM
ICS 49.030.20
English Version
Aerospace series - Spiral drive recesses for threaded
fasteners - Geometrical definition and technical
requirements
Série aérospatiale - Empreintes en spirale pour Luft- und Raumfahrt - Spiral-Innenantrieb für
éléments de fixation filetés - Définition géométrique et Schrauben - Definition der Geometrie und Technische
exigences techniques Anforderungen
This European Standard was approved by CEN on 14 July 2019.

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, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 4609:2019 E
worldwide for CEN national Members.

Contents
Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Required characteristics: configuration — dimensions — tolerances . 5
5 Designation. 7
6 Recess gauging . 7
7 General technical requirements . 11
7.1 Test apparatus. 11
7.1.1 Fixture . 11
7.1.2 Torsion machine . 11
7.1.3 Driver bit . 11
7.1.4 Test specimens . 11
8 Detail technical requirements . 12
Bibliography . 15

European foreword
This document (EN 4609:2019) has been prepared by the Aerospace and Defence Industries
Association of Europe - Standardization (ASD-STAN).
After enquiries and votes carried out in accordance with the rules of this Association, this Standard has
received the approval of the National Associations and the Official Services of the member countries of
ASD, prior to its presentation to CEN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2020, and conflicting national standards shall be
withdrawn at the latest by May 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: 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, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Introduction
Aerospace and Defence Standardisation (ASD-STAN) draws attention to the fact that it is claimed that
compliance with this document may involve the use of a patent “Spiral Drive System for Threaded
Fasteners” EP1025370B1.
ASD-STAN takes no position concerning the evidence, validity and scope of this patent right.
The holder of this patent right has assured ASD-STAN that he/she is willing to negotiate licences under
reasonable and non-discriminatory terms and conditions with applicants throughout the world. In this
respect, the statement of the holder of this patent right is registered with ASD-STAN. Information may
be obtained from:
Phillips Screw Company
301 Edgewater Place, Suite 320
Wakefield, Massachusetts 01880
U.S.A.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights other than those identified above. ASD-STAN shall not be held responsible for identifying
any or all such patent rights.
1 Scope
This European Standard specifies dimensions, tolerances, characteristics and qualification
requirements for MORTORQ Spiral Drive Recesses .
2 Normative references
There are no normative references in this document.
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