SIST EN 3725:2005
(Main)Aerospace series - Screws, pan head, six lobe recess, normal shank, long thread, in titanium alloy TI-P64001, anodized, MoS2 coated - Strength class: 1 100 MPa (at ambient temperature)
Aerospace series - Screws, pan head, six lobe recess, normal shank, long thread, in titanium alloy TI-P64001, anodized, MoS2 coated - Strength class: 1 100 MPa (at ambient temperature)
This standard specifies the characteristics of pan head screws with six lobe recess, threaded to head, in TI-P64001, anodised, MoS2 coated, for aerospace applications.
Strength class: 1 100 MPa
NOTE Taking account of the recess geometry, the strength class to be used for the seating torque calculation shall not be greater than 900 MPa.
Luft- und Raumfahrt - Zylinderschrauben, Sechs-Bogenzahn, langes Gewinde, aus Titanlegierung TI-P64001, anodisiert, MoS2-beschichtet - Festigkeitsklasse: 1 100 MPa (bei Raumtemperatur)
Série aérospatiale - Vis a tete cylindrique, a empreinte six lobes, fut normal, filetage long, en alliage de titane TI-P64001, anodisées, revetues MoS2 - Classe de résistance : 1 100 MPa (a température ambiante)
Aerospace series - Screws, pan head, six lobe recess, normal shank, long thread, in titanium alloy TI-P64001, anodized, MoS2 coated - Strength class: 1 100 MPa (at ambient temperature)
General Information
- Status
- Published
- Publication Date
- 31-May-2005
- Technical Committee
- SS SPL - Technical Board for the general field
- Current Stage
- 6060 - National Implementation/Publication (Adopted Project)
- Start Date
- 01-Jun-2005
- Due Date
- 01-Jun-2005
- Completion Date
- 01-Jun-2005
Relations
- Effective Date
- 01-Jun-2005
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
Overview
SIST EN 3725:2005 is a European standard developed under the Aerospace series, specifying the characteristics and requirements of titanium alloy screws designed for the stringent demands of aerospace applications. The screws described are pan head type with a six lobe (Torx-style) recess, normal shank, and long thread configuration, manufactured from titanium alloy TI-P64001. They are anodized and MoS2 (molybdenum disulphide) coated to enhance performance in critical environments. Their specified strength class is 1 100 MPa at ambient temperature, making them suitable for high-stress and high-performance aerospace assemblies.
Key Topics
- Product Specification: Defines pan head screws with six-lobe recess, threaded to the head, using titanium alloy TI-P64001 for durability and lightweight properties in aerospace environments.
- Surface Treatments: The fasteners are anodized to increase corrosion resistance and MoS2-coated for reduced friction, contributing to longer service life and easier assembly in aerospace structures.
- Mechanical Properties: Classified with a strength of 1 100 MPa at ambient temperature, suitable for demanding aircraft and space vehicle applications.
- Important Note: For seating torque calculations, the strength class value should not exceed 900 MPa due to the geometry of the six-lobe recess.
- Dimensional Standards: Includes comprehensive definitions of dimensions, tolerances, and compatible geometries, which ensure interchangeability and reliability in international aerospace supply chains.
- Marking and Traceability: Details specified product marking according to aerospace marking standards for full product identification and traceability.
Applications
Screws conforming to SIST EN 3725:2005 are designed primarily for aerospace engineering and related high-technology industries where both mechanical strength and reliability are critical. Typical applications include:
- Aircraft Structures: Use in airframes, fuselage assemblies, and control surfaces, where weight reduction without compromising strength is essential.
- Engines and Propulsion Systems: Suitable for fastening components where high strength and heat resistance are needed.
- Spacecraft: Ideal for use in launch vehicles, satellites, and other space-bound systems due to the combination of light weight, high strength, corrosion resistance, and wear protection.
- High-Performance Vehicles: Sometimes specified in advanced automotive or racing contexts requiring aerospace-grade fasteners.
- Precision Assemblies: Utilized in equipment and systems where exacting tolerances, secure fit, and ease of serviceability are priorities.
Related Standards
SIST EN 3725:2005 references and aligns with several key international standards in aerospace fastening. Relevant standards include:
- ISO 3353-1: Aerospace - Lead and runout threads (Rolled external threads)
- ISO 5855-2: Aerospace - MJ threads, Limit dimensions for bolts and nuts
- EN 2424: Marking of aerospace products
- EN 2491: Aerospace series - Molybdenum disulphide dry lubricants - Coating methods
- EN 3813: Titanium alloy TI-P64001 - Annealed bar and wire for forged fasteners
- EN 3818: Bolts, MJ threads, titanium alloy TI-P64001, strength class 1 100 MPa
- EN 3905: Six-lobe recesses for bolts - Technical specification
- EN 3911: Six-lobe recess - Geometrical definition
Complying with SIST EN 3725:2005 ensures compatibility with international aerospace quality management systems, facilitates acceptance in global supply chains, and supports improved safety and performance in critical applications.
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Frequently Asked Questions
SIST EN 3725:2005 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Aerospace series - Screws, pan head, six lobe recess, normal shank, long thread, in titanium alloy TI-P64001, anodized, MoS2 coated - Strength class: 1 100 MPa (at ambient temperature)". This standard covers: This standard specifies the characteristics of pan head screws with six lobe recess, threaded to head, in TI-P64001, anodised, MoS2 coated, for aerospace applications. Strength class: 1 100 MPa NOTE Taking account of the recess geometry, the strength class to be used for the seating torque calculation shall not be greater than 900 MPa.
This standard specifies the characteristics of pan head screws with six lobe recess, threaded to head, in TI-P64001, anodised, MoS2 coated, for aerospace applications. Strength class: 1 100 MPa NOTE Taking account of the recess geometry, the strength class to be used for the seating torque calculation shall not be greater than 900 MPa.
SIST EN 3725:2005 is classified under the following ICS (International Classification for Standards) categories: 49.030.20 - Bolts, screws, studs. The ICS classification helps identify the subject area and facilitates finding related standards.
SIST EN 3725:2005 has the following relationships with other standards: It is inter standard links to SIST EN 3725:2004, SIST EN 3818:2019, SIST EN 3911:2014, SIST EN 2491:2011, SIST EN 3905:2008, SIST EN 840-6:2004+A1:2008, SIST EN 2424:2008, SIST EN 3813:2014. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
SIST EN 3725:2005 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-junij-2005
1DGRPHãþD
SIST EN 3725:2004
Aerospace series - Screws, pan head, six lobe recess, normal shank, long thread,
in titanium alloy TI-P64001, anodized, MoS2 coated - Strength class: 1 100 MPa (at
ambient temperature)
Aerospace series - Screws, pan head, six lobe recess, normal shank, long thread, in
titanium alloy TI-P64001, anodized, MoS2 coated - Strength class: 1 100 MPa (at
ambient temperature)
Luft- und Raumfahrt - Zylinderschrauben, Sechs-Bogenzahn, langes Gewinde, aus
Titanlegierung TI-P64001, anodisiert, MoS2-beschichtet - Festigkeitsklasse: 1 100 MPa
(bei Raumtemperatur)
Série aérospatiale - Vis a tete cylindrique, a empreinte six lobes, fut normal, filetage long,
en alliage de titane TI-P64001, anodisées, revetues MoS2 - Classe de résistance : 1 100
MPa (a température ambiante)
Ta slovenski standard je istoveten z: EN 3725:2004
ICS:
49.030.20 Sorniki, vijaki, stebelni vijaki Bolts, screws, studs
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD
EN 3725
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2004
ICS 49.030.20 Supersedes EN 3725:2003
English version
Aerospace series - Screws, pan head, six lobe recess, normal
shank, long thread, in titanium alloy TI-P64001, anodized, MoS2
coated - Strength class: 1 100 MPa (at ambient temperature)
Série aérospatiale - Vis à tête cylindrique, à empreinte six Luft- und Raumfahrt - Zylinderschrauben, Sechs-
lobes, fût normal, filetage long, en alliage de titane TI- Bogenzahn, langes Gewinde, aus Titanlegierung TI-
P64001, anodisées, revêtues MoS2 - Classe de résistance P64001, anodisiert, MoS2 beschichtet - Festigkeitsklasse:
: 1 100 MPa (à température ambiante) 1 100 MPa (bei Raumtemperatur)
This European Standard was approved by CEN on 11 September 2003.
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 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 translation
under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official
versions.
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, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2004 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 3725:2004: E
worldwide for CEN national Members.
Contents Page
Foreword.3
1 Scope .4
2 Normative references .4
3 Required characteristics.4
4 Designation .9
5 Marking .9
6 Technical specifications .9
Foreword
This document (EN 3725:2004) has been prepared by the European Association of Aerospace
Manufacturers - Standardization (AECMA-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
AECMA, 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 2005, and conflicting national standards shall be withdrawn at
the latest by May 2005.
This document supersedes EN 3725:2003.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland
and United Kingdom.
1 Scope
This standard specifies the characteristics of pan head screws with six lobe recess, threaded to head, in
TI-P64001, anodized, MoS coated, for aerospace applications.
1)
Strength class: 1 100 MPa
NOTE Taking account of the recess geometry, the strength class to be used for the seating torque calculation shall
not be greater than 900 MPa.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 3353-1, Aerospace – Lead and runout threads – Part 1: Rolled external threads
ISO 5855-2, Aerospace – MJ threads – Part 2: Limit dimensions for bolts and nuts
EN 2424, Aerospace series – Marking of aerospace products
EN 2491, Aerospace series – Molybdenum disulphide dry lubricant
...



