prEN 2328

prEN 2328 is a CEN draft European Standard for aerospace tab washers in corrosion resisting steel, cadmium plated, used on flight control rods. It specifies the washer dimensions and related characteristics so the tab washer can lock the rod end to the rod body while still allowing a half-turn positional adjustment.

What does prEN 2328 specify?

prEN 2328 specifies the characteristics of tab washers for flight control rods. The document is focused on dimensions, material, surface treatment, marking, inspection, and quality assurance for parts used in flight control applications.

The scope is practical: these tab washers are meant to immobilise the rod end in relation to the rod body, while still allowing a positional adjustment of 1/2 a turn. That matters because the part must lock reliably without preventing final alignment during assembly.

The document is organised into:

• Clause 1 Scope
• Clause 2 Normative references
• Clause 3 Terms and definitions
• Clause 4 Required characteristics
• Clause 5 Designation
• Clause 6 Marking
• Clause 7 Inspections and tests
• Clause 8 Quality assurance
• Annex A, which is informative

What are the key requirements of prEN 2328?

prEN 2328 sets out the part geometry, the material and plating, how the part is identified, and how it is checked before use. In practice, this means a manufacturer must control both the physical shape and the production process so the washer performs as intended on a flight control rod.

Dimensions, mass and configuration

Clause 4.1 requires the configuration to follow Figure 1, and the dimensions and masses to follow Table 1. The dimensions apply after cadmium plating. For a buyer or engineer, this means the delivered part is controlled as a finished, plated item, not as an unfinished blank.

Surface condition

Clause 4.2 sets the surface roughness requirement at Ramax = 3,2 µm before cadmium plating. This is important because the surface finish before coating affects fit, coating quality, and consistency in assembly.

Material and surface treatment

Clause 4.3 requires carbon steel CR2 according to ISO 3574, with Rm ≥ 370 MPa. Clause 4.4 requires cadmium plating according to EN 2133, with a thickness of 10 µm to 20 µm. In practice, this tells the manufacturer both what steel to use and what corrosion-protective finish to apply.

Designation and identification

Clause 5 gives a designation format using the product name and a diameter code, for example WASHER TAB EN2328-08. Clause 6 requires each tab washer and its packaging to carry the identity block from Clause 5, in addition to the manufacturer’s own marking. This helps trace the correct size through production, receiving, and installation.

Visual inspection

Clause 7.1 requires visual examination for burrs, scratches and cracks, with the sample quantity linked to delivered quantity in Table 2. This gives a practical receiving or release check for surface defects that could weaken the part or interfere with assembly.

Bend test

Clause 7.2 requires a bend test on 0,1 % of the tab washers to be inspected, with a minimum of three parts. The tabs are folded 90° and straightened twice, then checked for visual cracks. This shows whether the material and forming process can withstand the locking operation.

Quality assurance

Clause 8 requires an approved production organization for aerospace products and a quality management system such as EN 9100 or an equivalent aerospace-accepted system. It also calls for a qualification procedure such as EN 9133 or an equivalent aerospace-accepted procedure, documented according to the specified tests unless otherwise agreed. For users, this means the part is not just dimensionally defined - the production and qualification process is also controlled.

Which standards are used with prEN 2328?

prEN 2328 refers to two normative documents and cites two aerospace quality documents as examples in Clause 8.

• EN 2133 - gives the cadmium plating requirements for steels and related alloys. It supports the surface treatment requirement in Clause 4.4.
• ISO 3574 - defines the cold-reduced carbon steel sheet quality used for the CR2 material in Clause 4.3.
• EN 9100 - cited as an example of an acceptable aerospace quality management system in Clause 8.
• EN 9133 - cited as an example of an acceptable aerospace qualification procedure in Clause 8.

Who uses prEN 2328?

prEN 2328 is used by aerospace manufacturers, suppliers, quality teams, and buyers working with flight control rod hardware. It is relevant for design, procurement, incoming inspection, production control, and qualification of tab washers intended for locking rod ends in flight control assemblies. It also supports test and quality personnel who need a defined bend test, appearance check, and traceable designation.

What changed in prEN 2328 from the previous edition?

prEN 2328 will supersede EN 2328:2006. The document states one significant technical change: the introduction of informative Annex A on bending test and installation example.

What does the prEN 2328 document contain?

prEN 2328 contains one configuration figure, one dimensional and mass table, and one sampling table for appearance inspection. It also gives the bend test method, the marking rules, the designation format, and the quality assurance expectations for aerospace production.

Annex A adds an informative bending test and installation example, which helps users understand how the tab washer is handled in practice. The bibliography lists EN 9100 and EN 9133 for quality management and qualification context.