SIST EN 2546:2009

• Abstract:

  This standard specifies the characteristics of lock washers in corrosion resisting steel, with radial serrations primarily intended for flight control rods.; These lock washers are intended to immobilise the rod end in relation to the rod body, whilst allowing a precise positional adjustment.

• Status: Published
• Publication Date: 15-Mar-2009
• ICS: 49.030.50 - Washers and other locking elements
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 19-Jan-2009
• Due Date: 26-Mar-2009
• Completion Date: 16-Mar-2009
• Ref Project: EN 2546:2006 - Aerospace series - Washers, lock with radial serrations in corrosion resisting steel passivated for flight control rods - Dimensions

• Replaces: SIST EN 2546:2001/AC1:2001 - Aerospace series - Washers, lock with radial serrations in corrosion resisting steel - Dimensions
• Effective Date: 01-Apr-2009
• Replaces: SIST EN 2546:2001 - Aerospace series - Washers, lock with radial serrations in corrosion resisting steel - Dimensions
• Effective Date: 01-Apr-2009
• Refers: SIST EN 9133:2018 - Aerospace series - Quality Management Systems - Qualification Procedure for Aerospace Standard Products
• Effective Date: 28-Jan-2026
• Refers: SIST EN 2516:2024 - Aerospace series - Passivation of corrosion resisting steels and decontamination of nickel or cobalt base alloys
• Effective Date: 28-Jan-2026

SIST EN 2546:2009 is the Slovenian adoption of EN 2546:2006 for aerospace lock washers with radial serrations in corrosion resisting steel, passivated for flight control rods. It specifies the washer types, dimensions, material, surface treatment, designation, marking and qualification needed for parts that immobilise the rod end relative to the rod body while still allowing precise positional adjustment.

What does SIST EN 2546:2009 specify?

SIST EN 2546:2009 specifies lock washers in corrosion resisting steel with radial serrations for flight control rods. The document is organized in six clauses that move from scope and references to product characteristics, designation, marking and qualification.

Clause	What it covers
1	Scope and intended use
2	Normative references
3	Required characteristics
4	Designation
5	Marking
6	Qualification

Clause 1 ties the washer to flight control rods and explains its function in the assembly. Clauses 3 to 5 are the practical user sections, because they tell a supplier what the part must look like, how to name it on drawings and orders, and how to mark it for identification. Clause 6 links the part to the aerospace qualification route.

What are the key requirements of SIST EN 2546:2009?

SIST EN 2546:2009 is mainly a dimensional and identification standard. The most important practical points are the washer geometry, the surface state, the allowed material, the part designation and the marking method.

Dimensions, mass and configuration

Clause 3.1 requires the configuration to match Figures 1 to 3, and the dimensions and masses to match Tables 1 and 2. In practice, this means the washer is not a generic locking washer - buyers and inspectors must check the exact coded sizes and the matching assembly thickness.

Surface finish

Clause 3.2 sets the surface roughness requirement. For production and inspection, this means the finished part needs a controlled surface condition, not just the correct shape.

Material and surface treatment

Clause 3.3 requires steel according to EN 2540 or EN 2538, with EN 2540 marked inactive for new design. Clause 3.4 requires passivation according to EN 2516. In practice, material selection and corrosion protection are part of conformity, not afterthoughts.

Functional form

The standard distinguishes the element on the rod body side and the element on the rod end side, shown in Figures 1 and 2, and the assembly thickness in Figure 3. This matters because the washer works as a paired functional part, not as a single loose disc.

Designation

Clause 4 defines the designation structure using the standard number, a code for the lock washer type, and the diameter code from Table 1. The note on code I9005 shows that the identification string can require an extra code in some cases, so purchasing and marking need to follow the prescribed order.

Marking

Clause 5 requires each lock washer and its packaging to carry the identity block from Clause 4, in addition to the manufacturer’s own marking. The marking method is left to the manufacturer, but it should be indelible when possible and must not damage the washer.

Qualification

Clause 6 requires qualification according to EN 9133. For suppliers, this means the part is not only a dimensional item - it is also covered by the aerospace standard-parts qualification process.

What terms does SIST EN 2546:2009 define?

• Lock washer assembly - The complete washer set identified by code C, used to lock the flight control rod adjustment.
• Element, rod body side - The washer element identified as code A and shown in Figure 1, positioned on the rod body side.
• Element, rod end side - The washer element identified as code B and shown in Figure 2, positioned on the rod end side.
• Passivation - The surface treatment required by EN 2516 to improve the corrosion-resisting steel surface condition.
• Identity block - The designation string used for marking and ordering, built from the standard number and the coded part identification.
• Qualification - The aerospace standard-part approval route required by EN 9133.
• Flight control rods - The application for which these lock washers are primarily intended.

Who uses SIST EN 2546:2009?

SIST EN 2546:2009 is used by aerospace manufacturers, suppliers of standard fasteners, and quality teams responsible for flight control hardware. Engineers use it to define the washer geometry and material in designs for control-rod assemblies. Buyers and inspectors use it to order the correct coded part, verify marking, and check conformity against the required dimensions, surface treatment and qualification route.

What changed in SIST EN 2546:2009 from the previous edition?

SIST EN 2546:2009 replaces SIST EN 2546:2001 and SIST EN 2546:2001/AC1:2001. The European edition EN 2546:2006 supersedes EN 2546:1988.

Which standards are used with SIST EN 2546:2009?

• EN 2516 - Defines passivation of corrosion resisting steels and decontamination of nickel base alloys; this controls the surface treatment required by Clause 3.
• EN 2538 - Specifies a steel grade that may be used for the washers.
• EN 2540 - Specifies another steel grade that may be used for the washers and is noted as inactive for new design.
• EN 9133 - Gives the qualification procedure for aerospace standard parts; Clause 6 points to this standard for approval.

What does the SIST EN 2546:2009 document contain?

The document contains three engineering figures and three tables that carry the core product information. Figures 1 and 2 show the two washer elements, and Figure 3 shows the assembly thickness. Tables 1 and 2 give the coded dimensions, serration count, angles and mass values used for specification and inspection. Table 3 links the functional washer type to the designation codes A, B and C. The designation example shows how the standard number and diameter code are combined for ordering and marking.

SLOVENSKI STANDARD
01-april-2009
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SIST EN 2546:2001
SIST EN 2546:2001/AC1:2001
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Aerospace series - Washers, lock with radial serrations in corrosion resisting steel
passivated for flight control rods - Dimensions
Luft- und Raumfahrt - Sicherungen, radialverzahnt aus korrosionsbeständigem Stahl,
passiviert für Bediengestänge von Flugsteuerungen - Maße
Série aérospatiale - Freins à stries radiales en acier résistant à la corrosion passivés
pour bielles de commandes de vol - Dimensions
Ta slovenski standard je istoveten z: EN 2546:2006
ICS:
49.030.50 Podložke in drugi blokirni Washers and other locking
elementi elements
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 2546
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2006
ICS 49.030.50 Supersedes EN 2546:1988
English Version
Aerospace series - Washers, lock with radial serrations in
corrosion resisting steel passivated for flight control rods -
Dimensions
Série aérospatiale - Freins à stries radiales en acier Luft- und Raumfahrt - Sicherungen, radialverzahnt aus
résistant à la corrosion passivés pour bielles de korrosionsbeständigem Stahl, passiviert für
commandes de vol - Dimensions Bediengestänge von Flugsteuerungen - Maße
This European Standard was approved by CEN on 26 October 2005.
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EUROPÄISCHES KOMITEE FÜR NORMUNG
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© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 2546:2006: E
worldwide for CEN national Members.

Contents Page
Foreword .3
1 Scope.4
2 Normative references.4
3 Required characteristics.4
4 Designation.6
5 Marking.7
6 Qualification.7

Foreword
This European Standard (EN 2546:2006) has been prepared by the European Association of Aerospace
Manufacturers - Standardization (AECMA-STAN).
After enquiries and votes carried out in accordance with the rules of this Association, this Standard has
received the approval of the National Associations and the Official Services of the member countries of
AECMA, 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 November 2006, and conflicti
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