Aerospace series - Bolt, large bihexagonal head, close tolerance normal shank, medium length thread, in heat resisting nickel base alloy, passivated - Classification: 1 250 MPa (at ambient temperature) /650 C

This standard specifies the characteristics of bolts, large bihexagonal head, close tolerance normal shank, medium length thread, in heat resisting nickel base alloy, passivated.
Classification: 1 250 MPa ) / 650 °C ).

Luft- und Raumfahrt - Zwölfkant-Passschrauben, mittlere Gewindelänge, aus hochwarmfester Nickelbasislegierung, passiviert, - Klasse: 1 250 MPa (bei Raumtemperatur)/650 °C

Diese Norm legt die Eigenschaften von Zwölfkant-Passschrauben mit mittlerer Gewindelänge, aus hoch¬warmfester Nickelbasislegierung, passiviert, fest.
Klasse: 1 250 MPa ) / 650 °C ).

Série aérospatiale - Vis à tête bihexagonale large, tige normale à tolérance serrée, filetage moyen, en alliage résistant à chaud à base de nickel, passivées - Classification: 1 250MPa (à température ambiante) / 650 °C

Aeronavtika - Sorniki z veliko dvanajstrobo glavo, ozka toleranca, srednja navojna dolžina, iz toplotnoodporne zlitine na nikljevi osnovi, pasivirani - Klasifikacija: 1250 MPa (pri temperaturi okolice)/650 °C

General Information

Status
Published
Publication Date
07-Apr-2009
ICS
49.030.20 - Bolts, screws, studs
Technical Committee
I13 - Imaginarni 13
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
03-Apr-2009
Due Date
08-Jun-2009
Completion Date
08-Apr-2009
Ref Project
EN 3444:2006 - Aerospace series - Bolt, large bihexagonal head, close tolerance normal shank, medium length thread, in heat resisting nickel base alloy, passivated - Classification: 1 250 MPa (at ambient temperature) /650 C

Overview

SIST EN 3444:2009 is a specialized European Standard established by CEN that governs aerospace-grade bolts with a large bihexagonal head. These bolts feature a close tolerance normal shank and a medium-length thread and are fabricated from a heat-resisting nickel-base alloy. The standard specifies bolts that are passivated to enhance corrosion resistance and are classified for use under demanding mechanical and thermal conditions-specifically, a tensile strength of 1,250 MPa at ambient temperature and usability up to 650 °C.

This standard ensures consistency, quality, and safety for aerospace applications where high strength and heat resistance are critical factors. It is widely adopted across European aerospace manufacturing and maintenance sectors, supporting interchangeability and reliability of fasteners in aeronautical engineering.

Key Topics

  • Bolt Configuration and Dimensions
    EN 3444 specifies the exact dimensions based on ISO 3186, including diameters, lengths, tolerances, and mass. The close tolerance shank and medium length thread are designed to meet the precision requirements of aerospace assemblies.

  • Material Specification
    The bolts must be manufactured from a heat-resistant nickel base alloy, chosen for its excellent mechanical strength and stability at elevated temperatures, ensuring performance up to 650 °C.

  • Surface Treatment & Passivation
    Passivation treatments conform to EN 2516 or EN 3769 standards. This process enhances corrosion resistance and surface quality, critical in aerospace environments exposed to variable atmospheric and thermal conditions.

  • Marking and Identification
    Bolts are marked as per EN 2424 using style C plus the MJ designation, allowing traceability and verification of compliance directly on the component.

  • Tolerance Requirements
    Form and positioning tolerances comply with ISO 7913, crucial for ensuring proper fit and function in aerospace assemblies where high precision is mandatory.

  • Manufacturing and Quality Control
    Manufacturer approval and bolt qualification adhere to EN 9100 and EN 9133 standards respectively, reflecting stringent aerospace quality management systems.

  • Oversized Bolts
    EN 3444 refers to EN 4016 for specifications regarding oversized bolt variants, expanding its applicability to non-standard size requirements.

Applications

  • Aerospace Fastening Systems
    These bolts are integral parts of aircraft and spacecraft structural assemblies, especially in environments exposed to high temperatures such as engine components and exhaust systems.

  • Heat-Resistant Assemblies
    The nickel base alloy and passivation ensure that the bolts maintain structural integrity and resist oxidation in heat-intensive aerospace components.

  • Defense and Aeronautical Manufacturing
    Defense contractors and aerospace manufacturers use EN 3444 bolts to meet strict standards for mechanical performance, traceability, and safety in flight-critical applications.

  • Maintenance, Repair, and Overhaul (MRO)
    These standardized bolts simplify maintenance operations by providing uniform specifications, enabling efficient replacement and inventory management.

Related Standards

  • EN 2424 - Marking of Aerospace Products
  • EN 2516 / EN 3769 - Passivation and Electrolytic Polishing of Nickel Base Alloys and Corrosion Resistant Steels
  • ISO 3186 - Dimensions for Large Bihexagonal Head Bolts
  • ISO 7913 - Tolerances of Form and Position for Bolts and Screws
  • EN 9100 / EN 9133 - Aerospace Quality Management and Qualification for Standard Parts
  • EN 4016 - Oversized Bolts in Aerospace Series
  • ISO 9154 - Technical Specification for Heat-Resistant Nickel-Based Alloy Bolts

Conclusion

SIST EN 3444:2009 delivers a comprehensive standard tailored for aerospace bolts demanding high tensile strength and thermal resistance. Combining tight dimensional tolerances, robust nickel-base alloy materials, and specialized passivation treatments, this standard supports critical aerospace engineering requirements. Manufacturers and engineers adopting EN 3444 ensure consistent bolt performance, safety, and reliability in demanding aeronautical applications, making it an indispensable reference in aerospace fastener specifications.

Keywords: Aerospace bolts, heat resistant nickel alloy, large bihexagonal head, passivated bolts, EN 3444, aerospace fastening standards, bolt tensile strength, medium thread length bolts, aerospace quality management, nickel-base alloy fasteners.

Frequently Asked Questions

SIST EN 3444:2009 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Aerospace series - Bolt, large bihexagonal head, close tolerance normal shank, medium length thread, in heat resisting nickel base alloy, passivated - Classification: 1 250 MPa (at ambient temperature) /650 C". This standard covers: This standard specifies the characteristics of bolts, large bihexagonal head, close tolerance normal shank, medium length thread, in heat resisting nickel base alloy, passivated. Classification: 1 250 MPa ) / 650 °C ).

This standard specifies the characteristics of bolts, large bihexagonal head, close tolerance normal shank, medium length thread, in heat resisting nickel base alloy, passivated. Classification: 1 250 MPa ) / 650 °C ).

SIST EN 3444:2009 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 3444:2009 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)


2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Aeronavtika - Sorniki z veliko dvanajstrobo glavo, ozka toleranca, srednja navojna dolžina, iz toplotnoodporne zlitine na nikljevi osnovi, pasivirani - Klasifikacija: 1250 MPa (pri temperaturi okolice)/650 °CLuft- und Raumfahrt - Zwölfkant-Passschrauben, mittlere Gewindelänge, aus hochwarmfester Nickelbasislegierung, passiviert, - Klasse: 1 250 MPa (bei Raumtemperatur)/650 °CSérie aérospatiale - Vis à tête bihexagonale large, tige normale à tolérance serrée, filetage moyen, en alliage résistant à chaud à base de nickel, passivées - Classification: 1 250MPa (à température ambiante) / 650 °CAerospace series - Bolt, large bihexagonal head, close tolerance normal shank, medium length thread, in heat resisting nickel base alloy, passivated - Classification: 1 250 MPa (at ambient temperature) /650
C49.030.20Sorniki, vijaki, stebelni vijakiBolts, screws, studsICS:Ta slovenski standard je istoveten z:EN 3444:2006SIST EN 3444:2009en,de01-maj-2009SIST EN 3444:2009SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 3444
July 2006 ICS 49.030.30 English Version
Aerospace series - Bolt, large bihexagonal head, close tolerance normal shank, medium length thread, in heat resisting nickel base alloy, passivated - Classification: 1 250 MPa (at ambient temperature) /650 °C
Série aérospatiale - Vis à tête bihexagonale large, tige normale à tolérance serrée, filetage moyen, en alliage résistant à chaud à base de nickel, passivées - Classification: 1 250MPa (à température ambiante) / 650 °C Luft- und Raumfahrt - Zwölfkant-Passschrauben, mittlere Gewindelänge, aus hochwarmfester Nickelbasislegierung, passiviert, - Klasse: 1 250 MPa (bei Raumtemperatur)/650 °C This European Standard was approved by CEN on 9 March 2006.
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, Romania, 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 © 2006 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 3444:2006: ESIST EN 3444:2009
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