SIST EN 3740:2026

• Abstract:

  This document specifies the characteristics of bolts, shouldered, thin hexagonal head, close tolerance shank, short thread, in titanium alloy, anodized, MoS2 dryfilm coated, for aerospace applications.; Classification: 1 100 MPa1/315 °C2..

• Status: Published
• Public Enquiry End Date: 24-Sep-2025
• Publication Date: 29-Sep-2026
• ICS: 49.025.30 - Titanium
• ICS: 49.030.20 - Bolts, screws, studs
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 29-Sep-2026
• Due Date: 04-Dec-2026
• Completion Date: 30-Sep-2026
• Ref Project: EN 3740:2026 - Aerospace series - Bolts, shouldered, thin hexagonal head, close tolerance shank, short thread, in titanium alloy, anodized, MoS2 coated - Classification: 1 100 MPa (at ambient temperature)/315 °C

• Revises: SIST EN 3740:2020 - Aerospace series - Bolts, shouldered, thin hexagonal head, close tolerance shank, short thread, in titanium alloy, anodized, MoS2 coated - Classification: 1 100 MPa (at ambient temperature)/315 °C
• Effective Date: 20-Nov-2024

Overview

SIST EN 3740:2026 is an aerospace standard for bolts, shouldered, thin hexagonal head, close tolerance shank, short thread, made from titanium alloy and finished with anodizing and MoS2 dryfilm coating. It defines the characteristics needed for aerospace applications where reliable fastening, controlled tolerances, and high performance are essential.

This standard is aligned with the classification 1 100 MPa at ambient temperature / 315 °C, making it relevant for demanding aerospace assembly environments. It also replaces EN 3740:2019, reflecting updated surface treatment requirements and editorial revisions.

The document supports consistent procurement, manufacturing, marking, and qualification of aerospace bolts. It is intended for use with compatible washers and nuts, helping ensure correct integration within aerospace fastening systems.

Key Topics

• Product type

  • Shouldered bolts
  • Thin hexagonal head
  • Close tolerance shank
  • Short thread

• Material and strength

  • Titanium alloy construction
  • Strength class 1 100 MPa
  • Designed for ambient temperature performance and elevated temperature use up to 315 °C

• Surface treatment

  • Anodized finish
  • MoS2 dryfilm coating
  • Coating application and coating method requirements are referenced in the standard

• Dimensional control

  • Configuration, dimensions, masses, and tolerances are specified
  • Form and position tolerances are linked to aerospace requirements
  • Dimensions apply after anodizing and coating

• Identification and conformity

  • Designation rules are included
  • Marking requirements are defined
  • Technical specification covers manufacturer approval, qualification, and mechanical testing expectations

Applications

SIST EN 3740:2026 is especially useful in aerospace supply chains and maintenance operations where standardized fastening components are required. Typical applications include:

• Aircraft and aerospace structural assemblies
• High-reliability bolted joints
• Component installations requiring close tolerance shanks
• Systems where titanium alloy fasteners help support weight-sensitive design goals
• Assemblies exposed to elevated temperatures and controlled surface conditions

The standard is also relevant for manufacturers, suppliers, quality teams, and procurement specialists working with aerospace standard products. It helps support interoperability, traceability, and consistent quality across production and qualification activities.

Related Standards

This aerospace bolt standard is connected to several important references:

• EN 2414 - Washers for aerospace applications
• EN 3230 - Nuts for aerospace fastening systems
• EN 2424 - Marking of aerospace products
• EN 2491 - Molybdenum disulphide dry lubricants and coating methods
• EN 4016 - Oversized bolts
• ISO 3353-1 - Lead and runout threads
• ISO 5855-2 - MJ threads and limit dimensions
• ISO 7913 - Tolerances of form and position
• ISO 9152 - Procurement specification for titanium alloy bolts
• EN 9100 - Quality management systems for aviation, space, and defence
• EN 9133 - Qualification procedure for aerospace standard products

For organizations working with aerospace titanium bolts, MoS2-coated fasteners, and titanium alloy aerospace standards, SIST EN 3740:2026 provides a clear framework for specification and compliance.

SLOVENSKI STANDARD
01-november-2026
Aeronavtika - Sorniki, vezi, tanka šesterokotna glava, ozka toleranca, kratek navoj,
iz titanove zlitine, anodizirani, mazani z MoS2 - Klasifikacija: 1100 MPa (pri
temperaturi okolice)/315 °C
Aerospace series - Bolts, shouldered, thin hexagonal head, close tolerance shank, short
thread, in titanium alloy, anodized, MoS2 coated - Classification: 1 100 MPa (at ambient
temperature)/315 °C
Luft- und Raumfahrt - Sechskant-Passschrauben, kleiner Kopf, enge Schafttoleranz,
kurzes Gewinde, aus Titanlegierung, anodisiert, MoS2‑geschmiert - Klasse: 1 100 MPa
(bei Raumtemperatur)/315 °C
Série aérospatiale - Vis épaulées, à tête hexagonale fine, tige à tolérance serrée, filetage
court, en alliage de titane, anodisées, revêtues MoS2 - Classification: 1 100 MPa (à
température ambiante)/315 °C
Ta slovenski standard je istoveten z: EN 3740:2026
ICS:
49.025.30 Titan Titanium
49.030.20 Sorniki, vijaki, stebelni vijaki Bolts, screws, studs
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 3740
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2026
EUROPÄISCHE NORM
ICS 49.030.20 Supersedes EN 3740:2019
English Version
Aerospace series - Bolts, shouldered, thin hexagonal head,
close tolerance shank, short thread, in titanium alloy,
anodized, MoS coated - Classification: 1 100 MPa (at
ambient temperature)/315 °C
Série aérospatiale - Vis épaulées, à tête hexagonale fine, Luft- und Raumfahrt - Sechskant-Passschrauben,
tige à tolérance serrée, filetage court, en alliage de kleiner Kopf, enge Schafttoleranz, kurzes Gewinde, aus
titane, anodisées, revêtues MoS - Classification : 1 100 Titanlegierung, anodisiert, MoS -geschmiert - Klasse: 1
2 2
MPa (à température ambiante)/315 °C 100 MPa (bei Raumtemperatur)/315 °C
This European Standard was approved by CEN on 3 August 2026.

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, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATIO N

EUROPÄISCHES KOMITEE FÜR NORMUN G

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 3740:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Required characteristics . 4
4.1 Configuration — Dimensions — Mass . 4
4.2 Tolerances of form and position . 5
4.3 Materials . 5
4.4 Surface treatment . 5
5 Designation . 9
6 Marking . 9
7 Technical specification . 9
8 Oversized bolts . 9
Bibliography. 10

European foreword
This document (EN 3740:2026) has been prepared by ASD-STAN.
After enquiries and votes carried out in accordance with the rules of this Association, this document has
received the approval of the National Associations and the Official Services of the member countries of
ASD-STAN, 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 March 2027, and conflicting national standards shall be
withdrawn at the latest by March 2027.
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.
This document supersedes EN 3740:2019.
This document includes the following significant technical changes with respect to EN 3740:2019:
— 4.4 “Surface treatment”, restrictions for coating (“code G or code J”) deleted;
— document editorially revised.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations 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 Nort
...