kSIST FprEN 4266:2026

Aerospace series - Bearing spherical plain, metal to metal, in corrosion resisting steel, cadmium plated - Wide series - Dimensions and loads - Inch series

This document specifies the characteristics of spherical plain bearings, metal to metal, in corrosion resisting steel, cadmium plated and chromated, wide series, inch series for aerospace applications.
Spherical plain bearings, metal to metal, in corrosion resisting steel, cadmium plated and chromated, wide series, are intended for use in fixed or moving parts of the aircraft structure and their control mechanisms.
Spherical plain bearings, metal to metal, in corrosion resisting steel, cadmium plated and chromated, wide series, are intended for use in the temperature range −54 °C to 150 °C, and intended to be lubricated by means of the following greases:
- Code A: grease conforming to MIL-PRF-23827, operating temperature range −73 °C to 121 °C;
- Code B: grease conforming to MIL-PRF-81322, operating temperature range −54 °C to 177 °C.
For the purposes of this document, the range of application for bearings lubricated with grease conforming to code A is limited to 121 °C.
For the purposes of this document, the range of applications for bearings lubricated with grease conforming to code B is limited to 177 °C.
NOTE In both cases it is important to provide the spherical surface of the outer or inner ring with a dry-film lubricant conforming to MIL-PRF-46010 or equivalent (anti-seizing protection).

Luft- und Raumfahrt - Gelenklager, Metall auf Metall, aus korrosionsbeständigem Stahl, kadmiert - Breite Reihe - Maße und Belastungen - Inch Reihe

No Scope available

Série aérospatiale - Rotule lisse, métal à métal en acier résistant à la corrosion, cadmiée - Série large - Dimensions et charges - Série en inches

Le présent document spécifie les caractéristiques des rotules lisses, métal à métal, en acier résistant à la corrosion, cadmiées et chromatées, série large, série en inches, pour les applications aérospatiales.
Les rotules lisses, métal à métal, en acier résistant à la corrosion, cadmiées et chromatées, série large, sont destinées à être utilisées pour les parties fixes ou mobiles de la structure de l’aéronef et leurs mécanismes de commande.
Les rotules lisses, métal à métal, en acier résistant à la corrosion, cadmiées et chromatées, série large, sont destinées à être utilisées dans une plage de températures de −54 °C à 150 °C, et à être lubrifiées à l’aide des graisses suivantes :
—   code A : graisse conforme à la MIL-PRF-23827, plage de températures de fonctionnement de −73 °C à 121 °C ;
—   code B : graisse conforme à la MIL-PRF-81322, plage de températures de fonctionnement de −54 °C à 177 °C.
Pour les besoins du présent document, la plage d’application des rotules lubrifiées à l’aide de graisse conforme au code A est limitée à 121 °C.
Pour les besoins du présent document, la plage d’application des rotules lubrifiées à l’aide de graisse conforme au code B est limitée à 177 °C.
NOTE   Dans les deux cas, il est important d'appliquer sur la surface sphérique de la bague extérieure ou intérieure un lubrifiant à film sec conforme à la MIL-PRF-46010 ou équivalente (protection anti-grippage).

Aeronavtika - Ležaj, krogelni, drsni, kovina na kovino, iz korozijsko odpornega jekla, kadmiran - Široki tip - Mere in obremenitve - Colske serije

General Information

• Status: Not Published
• Public Enquiry End Date: 19-Nov-2024
• ICS: 21.100.01 - Bearings in general
• ICS: 49.035 - Components for aerospace construction
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 5020 - Formal vote (FV) (Adopted Project)
• Start Date: 07-May-2026
• Due Date: 25-Jun-2026
• Completion Date: 08-May-2026
• Ref Project: FprEN 4266 - Aerospace series - Bearing spherical plain, metal to metal, in corrosion resisting steel, cadmium plated - Wide series - Dimensions and loads - Inch series

Relations

• Revises: SIST EN 4266:2014 - Aerospace series - Bearing spherical plain, metal to metal, in corrosion resisting steel, cadmium plated - Wide series - Dimensions and loads - Inch series
• Effective Date: 03-May-2023

Overview

kSIST FprEN 4266:2026 defines the specifications for aerospace-grade spherical plain bearings, metal-to-metal contact, constructed from corrosion-resisting steel with cadmium plating and chromate finishing. This wide series, inch-based standard, developed by SIST and harmonized under European standards, outlines essential requirements regarding the dimensions, mass, tolerances, materials, and load capacities for these specialized bearings. The standard supports their use in both fixed and moving parts of aircraft structures and control mechanisms, ensuring reliable performance in aerospace applications.

Key Topics

• Material Requirements
  Spherical plain bearings must be manufactured from corrosion-resisting steel, defined by referenced standards for inner and outer ring materials, to provide durability and resistance to harsh environmental factors.

• Surface Treatment
  Bearing components receive cadmium plating and chromating to enhance corrosion resistance, critical in aerospace environments. Dry-film lubricant application is also specified for anti-seizing protection.

• Series and Sizing
  This standard focuses on the wide series of inch-based bearings, providing comprehensive tables for dimensions, tolerances, and mass, thus ensuring compatibility and interchangeability in international aerospace industries.

• Load Ratings and Clearance
  Detailed permissible and ultimate load capacities (radial and axial) are documented, with separate values for lubrication codes and special considerations on installation types. This information is vital for safe bearing selection and application in aircraft systems.

• Temperature Ranges and Lubrication
  Bearings specified by kSIST FprEN 4266:2026 are designed to operate from −54°C to 150°C, with upper operational limits determined by the type of grease used:

  • Code A: MIL-PRF-23827 grease, for −73°C to 121°C
  • Code B: MIL-PRF-81322 grease, for −54°C to 177°C Applications above 121°C require Code B lubricant, while all require proper dry-film lubrication for optimal performance.

• Product Identification
  The standard describes the complete bearing designation, covering reference number, grease code, clearance code, diameter code, grease hole code, and grooving code for accurate identification and ordering.

Applications

Spherical plain bearings covered by this standard are ideally suited for:

• Aircraft Structures
  Utilized in fixed or articulating joints throughout the airframe to accommodate multidirectional loads, essential for wing, fuselage, and landing gear assemblies.

• Control Mechanisms
  Integral to linkages, actuators, and pivot points where precise movement and low friction are desired, withstanding both static and dynamic operational loads.

• Harsh Environments
  The corrosion-resistant, cadmium-plated finish, and compatibility with specialized lubricants, make these bearings suitable for use in environments with exposure to moisture, temperature extremes, and other challenging aerospace conditions.

• Maintenance and Replacement
  Standardized dimensions, load ratings, and clearances facilitate easy replacement and reduce downtime during scheduled maintenance and overhaul of aerospace systems.

Related Standards

For implementation and reference, kSIST FprEN 4266:2026 should be considered alongside these key standards:

• EN 2030 - Aerospace series: Steel grade and conditioning for the inner ring
• EN 2133 - Cadmium plating requirements for aerospace steels
• EN 2337 - Technical specification for spherical plain bearings
• EN 3161 - Material specification for outer ring steel
• EN 2424 - Marking specifications for aerospace products
• ISO 1132-1 - Rolling bearings: Terminology and tolerances
• ISO 8075 - Surface treatment protocols for stainless steel aerospace parts
• TR 4475 / TR 4661 - Bearings vocabulary, materials, and surface treatments
• MIL-PRF-23827 / MIL-PRF-81322 / MIL-PRF-46010 - US military grease and dry-film lubricant specifications

Adhering to these standards ensures that bearings meet international aerospace requirements for safety, performance, and traceability.

Keywords: aerospace bearings, spherical plain bearings, corrosion-resisting steel, cadmium plated bearings, inch series, aircraft structure parts, control mechanism bearings, kSIST FprEN 4266, bearing lubrication, wide series bearings, dimensions and loads.

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN 4266:2024
01-november-2024
Aeronavtika - Ležaj, krogelni, drsni, kovina na kovino, iz korozijsko odpornega
jekla, kadmiran - Široki tip - Mere in obremenitve - Colske serije
Aerospace series - Bearing spherical plain, metal to metal, in corrosion resisting steel,
cadmium plated - Wide series - Dimensions and loads - Inch series
Luft- und Raumfahrt - Gelenklager, Metall auf Metall, aus korrosionsbeständigem Stahl,
kadmiert - Breite Reihe - Maße und Belastungen - Inch Reihe
Série aérospatiale - Rotule lisse, métal à métal en acier résistant à la corrosion, cadmiée
- Série large - Dimensions et charges - Série en inches
Ta slovenski standard je istoveten z: prEN 4266
ICS:
21.100.01 Ležaji na splošno Bearings in general
49.035 Sestavni deli za letalsko in Components for aerospace
vesoljsko gradnjo construction
oSIST prEN 4266:2024 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN 4266:2024
oSIST prEN 4266:2024
DRAFT
EUROPEAN STANDARD
prEN 4266
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2024
ICS 49.035 Will supersede EN 4266:2013
English Version
Aerospace series - Bearing spherical plain, metal to metal,
in corrosion resisting steel, cadmium plated - Wide series -
Dimensions and loads - Inch series
Série aérospatiale - Rotule lisse, métal à métal en acier Luft- und Raumfahrt - Gelenklager, Metall auf Metall,
résistant à la corrosion, cadmiée - Série large - aus korrosionsbeständigem Stahl, kadmiert - Breite
Dimensions et charges - Série en inches Reihe - Maße und Belastungen - Inch Reihe
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
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 4266:2024 E
worldwide for CEN national Members.

oSIST prEN 4266:2024
prEN 4266:2024 (E)
Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 5
4 Symbols and abbreviations . 5
5 Requirements . 5
5.1 Configuration, dimensions, tolerances and mass. 5
5.2 Surface roughness . 5
5.3 Material . 5
5.4 Surface treatment . 6
5.5 Loads and clearances . 6
6 Designation . 13
7 Marking . 14
8 Technical specification . 14
Bibliography . 15
oSIST prEN 4266:2024
prEN 4266:2024 (E)
European foreword
This document (prEN 4266:2024) has been prepared by the Aerospace and Defence Industries
Association of Europe — Standardization (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 4266:2013.
prEN 4266:2024 includes the following significant technical changes with respect to EN 4266:2013:
— Value for the outer diameter for diameter code 05 in Table 1 corrected;
— Reference on TR 4661 for alternative materials added.
— Reference on TR 4661 for alternative materials added.
oSIST prEN 4266:2024
prEN 4266:2024 (E)
1 Scope
This document specifies the characteristics of spherical plain bearings, metal to metal, in corrosion
resisting steel, cadmium plated and chromated, wide series, inch series for aerospace applications.
They are intended for use in fixed or moving parts of the aircraft structure and their control
mechanisms.
They are used in the temperature range − 54 °C to 150 °C. As they are lubricated by means of the
following greases:
— Code A: Grease as per MIL-PRF-23827C, operating temperature range − 73 °C to 121 °C;
— Code B: Grease as per MIL-PRF-81322G, operating temperature range − 54 °C to 177 °C.
The range of application for bearings lubricated with grease per code A is limited to 121 °C.
In both cases it is important to provide the spherical surface of the outer or inner ring with a dry-film
lubricant as per MIL-PRF-46010G or equivalent (anti-seizing protection).
The slide hole treatment either at the outer ring or inner ring.
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 2030, Aerospace series — Steel X105CrMo17 (1.3544) — Hardened and tempered — Bars — De ≤
150 mm
EN 2133, Aerospace series — Cadmium plating of steels with specified tensile strength ≤ 1 450 MPa,
copper, copper alloys and nickel alloys
EN 2337, Aerospace series — Spherical plain bearings — Technical specification
EN 2424, Aerospace series — Marking of aerospace products
EN 3161, Aerospace series — Steel FE-PM3801 (X5CrNiCu17-4) — Air melted, solution treated and
precipitation treated, bar a or D ≤ 200 mm, Rm ≥ 930 MPa
ISO 1132-1, Rolling bearings — Tolerances — Part 1: Terms and definitions
ISO 8075, Aerospace — Surface treatment of hardenable stainless steel parts
TR 4475, Aerospace series — Bearings and mechanical transmissions for airframe applications —
Vocabulary
TR 4661, Aerospace series — Bearings, flight controls — Materials and surface treatments

Published as ASD-STAN Technical Report at the date of publication of this document (www.asd-stan.org).
oSIST prEN 4266:2024
prEN 4266:2024 (E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in TR 4475 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
4 Symbols and abbreviations
Symbols of limit deviations are in accordance with definitions of ISO 1132-1.
α is the maximum angle of tilt of the outer ring with respect to the inner ring, with the
spherical surface of the outer ring being completely in contact with the inner ring;
C is the permissible static axial load;
a
C is the permissible static
...