FprEN 3293

Aerospace series - Bolts, T-head, close tolerance, medium thread length, in heat resisting nickel base alloy NI-P100HT (Inconel 718), uncoated - Classification: 1 275 MPa/650 °C

This document specifies the dimensions of uncoated T-head bolts, close tolerance, with MJ-thread, medium thread length, in heat-resisting nickel base alloy NI-P100HT for aerospace applications.
Maximum test temperature of the parts is 650 °C.
These bolts are used in aerospace fastening systems mainly stressed in shearing force.

Luft- und Raumfahrt - T-Kopf-Passschrauben, mittlere Gewindelänge, aus hochwarmfester Nickelbasislegierung NI-P100HT (Inconel 718), blank - Klasse: 1 275 MPa/650 °C

Dieses Dokument legt die Maße von blanken T-Kopf-Passschrauben mit MJ-Gewinde mittlerer Gewindelänge aus hochwarmfester Nickelbasislegierung NI P100HT für die Verwendung in der Luft- und Raumfahrt fest.
Die maximale Prüftemperatur der Teile beträgt 650 °C.
Diese Schrauben sind in Verbindungssystemen der Luft- und Raumfahrt zu verwenden, die hauptsächlich auf Scherkraft beansprucht werden.

Série aérospatiale - Vis de précision à tête anti-rotation en T, filetage moyen, en alliage résistant à chaud base nickel NI-P100HT (Inconel 718), non revêtues - Classification : 1 275 MPa/650 °CC

Le présent document spécifie les dimensions des vis de précision à tête anti-rotation en T, à filetage MJ moyen, en alliage résistant à chaud base nickel NI-P100HT, pour les applications aérospatiales.
La température maximale d'essai des pièces est de 650 °C.
Ces vis sont à utiliser dans les systèmes de fixation aérospatiaux essentiellement soumis à des efforts de cisaillement.

Aeronavtika - Sorniki, glava T, ozka toleranca, srednja navojna dolžina, iz toplotnoodporne zlitine na nikljevi osnovi NI-P100HT (Inconel 718), brez prevleke - Klasifikacija: 1 275 MPa/650 °C

General Information

• Status: Not Published
• Publication Date: 29-Nov-2026
• ICS: 49.030.20 - Bolts, screws, studs
• Technical Committee: ASD-STAN - Aerospace
• Drafting Committee: ASD-STAN/D 3/S 2 - Fasteners
• Current Stage: 4599 - Dispatch of FV draft to CMC - Finalization for Vote
• Start Date: 24-Apr-2026
• Completion Date: 24-Apr-2026
• Ref Project: oSIST prEN 3293:2025 - Aerospace series - Bolts, T-head, close tolerance, medium thread length, in heat resisting nickel base alloy NI-P100HT (Inconel 718), uncoated - Classification: 1 275 MPa/650 °C

Relations

• Revises: EN 3293:2008 - Aerospace series - Bolts, T-head, close tolerance, medium thread length, in heat resisting nickel base alloy NI-P100HT (Inconel 718), uncoated - Classification: 1 275 MPa/650 °C
• Effective Date: 12-Feb-2025

Overview

FprEN 3293 is a draft European Standard developed by CEN, specifying requirements for aerospace T-head bolts made from heat-resisting nickel base alloy NI-P100HT (commonly known as Inconel 718). These uncoated bolts feature close tolerances and medium thread lengths using the MJ thread profile, and are designed to withstand service loads up to 1 275 MPa at temperatures up to 650 °C. The primary application of these bolts is in aerospace fastening systems, where shear forces dominate.

This standard supersedes EN 3293:2008, introducing updates such as the inclusion of the SAE AMS5662 material standard and slight modifications to thread surface requirements.

Key Topics

• Scope and Application: Covers dimensions, tolerances, mass, and required characteristics of uncoated, close-tolerance T-head bolts in NI-P100HT.
• Material Specification: The bolts are manufactured from nickel base alloy NI-P100HT (Inconel 718), offering high resistance to heat and corrosion.
• Thread Profile: The standard specifies MJ-thread (ISO metric, with rounded root and crest), typical for aerospace applications due to its high fatigue tolerance.
• Performance Classification: Designed for a maximum test temperature of 650 °C and capable of supporting 1 275 MPa of stress, making them suitable for extreme aerospace environments.
• Marking and Designation: Clear rules for the designation and marking of bolts for traceability and consistency in aerospace manufacturing.
• No Surface Coating: These bolts are supplied uncoated, relying on the corrosion and oxidation resistance of Inconel 718.

Applications

FprEN 3293 T-head bolts are critical components within the aerospace industry, specifically:

• Aircraft structures: Used in joints and assemblies where precise fit and resistance to shearing forces are essential.
• Engine and exhaust assemblies: Suitable for high-temperature environments due to the heat-resistant properties of Inconel 718.
• Fastening systems: Integrated into airframes, nacelles, and other high-stress regions where close tolerance and robust mechanical properties are required.

The bolts’ close tolerance ensures minimal play and enhanced shear strength, crucial in applications where reliability and safety are paramount.

Related Standards

The following standards are referenced in FprEN 3293 and are important for comprehensive compliance and understanding:

• EN 2424: Marking of aerospace products.
• EN 2583: Bolts with MJ threads in heat-resisting nickel base alloys - provides relevant technical specifications.
• ISO 3353-1 & ISO 5855 (parts 1 & 2): Specifications for lead, runout threads, and general requirements for MJ threads.
• TR 3775: Guidance on materials for bolts and pins.
• SAE AMS5662: Nickel alloy composition and treatment requirements for Inconel 718 components.

For manufacturers and quality assurance teams, referencing these standards ensures that T-head bolts meet the rigorous demands of the aerospace sector and are compatible with other standardized components.

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Ensuring compliance with FprEN 3293 helps drive quality, safety, and reliability in aerospace fastening applications, leveraging robust nickel base alloys, precise close tolerance design, and internationally recognized MJ threading for demanding environments.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2025
Aeronavtika - Sorniki, glava T, ozka toleranca, srednja navojna dolžina, iz
toplotnoodporne zlitine na nikljevi osnovi NI-P100HT (Inconel 718), brez prevleke -
Klasifikacija: 1 275 MPa/650 °C
Aerospace series - Bolts, T-head, close tolerance, medium thread length, in heat
resisting nickel base alloy NI-P100HT (Inconel 718), uncoated - Classification: 1 275
MPa/650 °C
Luft- und Raumfahrt - T-Kopf-Passschrauben, mittlere Gewindelänge, aus
hochwarmfester Nickelbasislegierung NI-P100HT (Inconel 718), blank - Klasse: 1 275
MPa/650 °C
Série aérospatiale - Vis de précision à tête bihexagonale, à filetage moyen, en alliage
résistant à chaud à base de nickel NI-P100HT (Inconel 718), non revêtu - Classification :
1 275 MPa/650 °C
Ta slovenski standard je istoveten z: prEN 3293
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.

DRAFT
EUROPEAN STANDARD
prEN 3293
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2025
ICS 49.030.20 Will supersede EN 3293:2008
English Version
Aerospace series - Bolts, T-head, close tolerance, medium
thread length, in heat resisting nickel base alloy NI-
P100HT (Inconel 718), uncoated - Classification: 1 275
MPa/650 °C
Série aérospatiale - Vis de précision à tête Luft- und Raumfahrt - T-Kopf-Passschrauben, mittlere
bihexagonale, à filetage moyen, en alliage résistant à Gewindelänge, aus hochwarmfester
chaud à base de nickel NI-P100HT (Inconel 718), non Nickelbasislegierung NI-P100HT (Inconel 718), blank -
revêtu - Classification : 1 275 MPa/650 °C Klasse: 1 275 MPa/650 °C
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee ASD-
STAN.
If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 3293:2025 E
worldwide for CEN national Members.

prEN 3293:2025 (E)
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, tolerances, masses . 4
4.2 Material . 8
4.3 Surface treatment . 8
5 Designation . 8
6 Marking . 8
7 Technical specification . 8

prEN 3293:2025 (E)
European foreword
This document (prEN 3293:2025) 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 document is currently submitted to the CEN Enquiry.
This document will supersede EN 3293:2008.
prEN 3293:2025 includes the following significant technical changes with respect to EN 3293:2008:
— material standard SAE AMS5662 added;
— 3.4 “Thread surface” removed.
prEN 3293:2025 (E)
1 Scope
This document specifies the dimensions of uncoated T-head bolts, close tolerance, with MJ-thread,
medium thread length, in heat-resisting nickel base alloy NI-P100HT for aerospace applications.
Maximum test temperature of the parts is 650 °C.
These bolts are used in aerospace fastening systems mainly stressed in shearing force.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
EN 2424, Aerospace series — Marking of aerospace products
EN 2583, Aerospace series — Bolts, MJ threads, in heat resisting nickel base alloy NI-PH2601
(Inconel 718) — Classification: 1 275 MPa (at ambient temperature)/650°C — Technical specification
ISO 3353-1, Aerospace — Lead and runout threads — Part 1: Rolled external threads
ISO 5855-1, Aerospace — MJ threads — Part 1: General requirements
ISO 5855-2, Aeros
...