FprEN 3636

Aerospace series - Screws, reduced pan head, offset cruciform recess, relieved shank, long thread, in heat resisting steel FEPA92HT (A286), silver plated - Classification: 900 MPa/650 °C

This document specifies the requirements for offset cruciform recess pan head screws with relieved shank and long thread in heat resisting steel FE-PA92HT, silver plated, tensile strength class 900 MPa at room temperature. The maximum test temperature of the material is 650 °C.

Luft- und Raumfahrt - Flachkopfschrauben mit geripptem Flügelkreuzschlitz, Dünnschaft, langes Gewinde, aus hochwarmfestem Stahl FE‑PA92HT (A286), versilbert - Klasse: 900 MPa/650 °C

Dieses Dokument legt die Anforderungen an Flachkopfschrauben mit Flügelkreuzschlitz, Dünnschaft und langem Gewinde aus hochwarmfestem Stahl FE PA92HT, versilbert, in der Zugfestigkeitsklasse 900 MPa bei Raumtemperatur fest. Die maximale Prüftemperatur des Werkstoffes beträgt 650 °C.

Série aérospatiale - Vis à tête cylindrique, réduite, à empreinte cruciforme déportée, tige dégagée, filetage long, en acier résistant à chaud FE-PA92HT (A286), argentées - Classification : 900 MPa/650 °C

Le présent document spécifie les exigences pour les vis à tête cylindrique, à empreinte cruciforme déportée, tige dégagée et filetage long, en acier résistant à chaud FE-PA92HT (A286), argentées, de classe de résistance à la traction de 900 MPa à température ambiante. La température maximale d’essai du matériau est de 650 °C

Aeronavtika - Vijaki, nizka valjasta glava, križna zareza, dolgi navoj do glave, iz toplotnoodpornega jekla FE-PA92HT (A286), posrebreni - Klasifikacija: 900 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 3636:2025 - Aerospace series - Screws, reduced pan head, offset cruciform recess, relieved shank, long thread, in heat resisting steel FEPA92HT (A286), silver plated - Classification: 900 MPa/650 °C

Relations

• Revises: EN 3636:2008 - Aerospace series - Screws, reduced pan head, offset cruciform recess, relieved shank, long thread, in heat resisting steel FE-PA92HT (A286), silver plated - Classification: 900 MPa/650 °C
• Effective Date: 23-Oct-2024

Overview

FprEN 3636 is a European draft standard published by CEN, specifying requirements for screws used in aerospace applications. These screws feature a reduced pan head, an offset cruciform recess, a relieved shank, and a long thread. They are manufactured from heat resisting steel FEPA92HT (A286) and are silver plated for enhanced durability and corrosion resistance. The specification covers screws in the 900 MPa tensile strength class at room temperature, designed to perform in environments with maximum material test temperatures of 650 °C. This standard ensures high-strength, heat-resistant fasteners suitable for demanding aerospace applications.

Key Topics

• Aerospace-quality screws: Focused on screws with reduced pan heads and offset cruciform recesses, supporting secure fastening and reliable performance in critical aerospace assemblies.
• Material requirements: The screws are made from FEPA92HT (A286), a type of heat resisting steel, meeting high standards for temperature performance and mechanical strength.
• Surface coating: Screws are silver plated according to EN 2786, which provides corrosion resistance and improved conductivity-essential in aerospace environments.
• Mechanical properties: Classification covers a tensile strength of 900 MPa at room temperature, with operation suitability up to 650 °C.
• Dimensional consistency: The standard defines configuration, dimensions, and tolerances to ensure interchangeability and reliable fit during assembly.
• Marking requirements: Includes specifications for screw identification based on EN 2424, ensuring clear traceability and compliance in manufacturing and supply chains.

Applications

Fasteners conforming to FprEN 3636 are primarily used in:

• Aircraft assembly: The high strength and heat resistance make these screws suitable for securing components in engine compartments, airframes, and critical structural assemblies.
• Aerospace environments: Designed for use in environments exposed to high temperatures and demanding operational loads.
• Maintenance and repair: The clear designation and standardized dimensions ensure ease of replacement and compatibility in routine aerospace maintenance.
• Other high-performance engineering: Outside aerospace, any application requiring resilient, heat-resistant, silver-plated fasteners may benefit from components manufactured according to this standard.

By specifying both material and plating requirements, this standard helps extend component lifespan, reduce maintenance needs, and support reliability in safety-critical systems.

Related Standards

Standards referenced within FprEN 3636 include:

• EN 2398, EN 2399: Relate to heat resisting steel materials for aerospace fasteners.
• EN 2424: Standard for marking aerospace products, ensuring traceability.
• EN 2786: Governs electrolytic silver plating for fasteners.
• EN 3043: Technical specification for fasteners in heat resisting steel FEPA92HT (A286).
• ISO 3353-1: Covers rolled external threads for aerospace screws.
• ISO 5855-1, ISO 5855-2: Specify MJ thread general requirements and dimensions.
• ISO 14275, ISO 14277, ISO 14278: Define details for offset cruciform recess drives, associated tools, and gauges for metric series fasteners.

Adhering to these related aerospace standards ensures compatibility, performance, and safety in international supply chains and assembly operations.

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By following FprEN 3636 and referenced standards, aerospace manufacturers and suppliers ensure their fasteners are robust, traceable, and suitable for modern high-performance applications in aviation and beyond.

Standards Content (Sample)

SLOVENSKI STANDARD
01-oktober-2025
Aeronavtika - Vijaki, nizka valjasta glava, križna zareza, dolgi navoj do glave, iz
toplotnoodpornega jekla FE-PA92HT (A286), posrebreni - Klasifikacija: 900
MPa/650 °C
Aerospace series - Screws, reduced pan head, offset cruciform recess, relieved shank,
long thread, in heat resisting steel FEPA92HT (A286), silver plated - Classification: 900
MPa/650 °C
Luft- und Raumfahrt - Flachkopfschrauben mit geripptem Flügelkreuzschlitz, Dünnschaft,
langes Gewinde, aus hochwarmfestem Stahl FE‑PA92HT (A286), versilbert - Klasse:
900 MPa/650 °C
Série aérospatiale - Vis à tête cylindrique, réduite, à empreinte cruciforme déportée, à
tige réduite, à filetage long, en acier résistant à chaud FE-PA92HT (A286), argentées -
Classification: 900 MPa/650 °C
Ta slovenski standard je istoveten z: prEN 3636
ICS:
49.025.10 Jekla Steels
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 3636
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2025
ICS 49.030.20 Will supersede EN 3636:2008
English Version
Aerospace series - Screws, reduced pan head, offset
cruciform recess, relieved shank, long thread, in heat
resisting steel FEPA92HT (A286), silver plated -
Classification: 900 MPa/650 °C
Série aérospatiale - Vis à tête cylindrique, réduite, à Luft- und Raumfahrt - Flachkopfschrauben mit
empreinte cruciforme déportée, à tige réduite, à geripptem Flügelkreuzschlitz, Dünnschaft, langes
filetage long, en acier résistant à chaud FE-PA92HT Gewinde, aus hochwarmfestem Stahl FE-PA92HT
(A286), argentées - Classification: 900 MPa/650 °C (A286), versilbert - Klasse: 900 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 3636:2025 E
worldwide for CEN national Members.

prEN 3636:2025 (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 . 4
4.2 Material . 5
4.3 Surface coating . 5
5 Designation . 8
6 Marking . 8
7 Technical specification . 8
prEN 3636:2025 (E)
European foreword
This document (prEN 3636:2025) 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
...