oSIST prEN 2328:2026

oSIST prEN 2328:2026 is a draft European Standard from CEN, prepared by ASD-STAN, for tab washers in corrosion resisting steel, cadmium plated, for flight control rods. It specifies the dimensions and related characteristics of these washers for aerospace use, where the part must lock the rod end to the rod body while still allowing a half-turn positional adjustment.

What does oSIST prEN 2328:2026 specify?

oSIST prEN 2328:2026 specifies the characteristics of tab washers for flight control rods and organizes them into clauses for scope, normative references, terms and definitions, required characteristics, designation, marking, inspections and tests, and quality assurance. It also includes an informative Annex A on bending test and installation example.

The scope is narrow and practical: the standard is about one washer type used in flight control rod assemblies. That matters because buyers and engineers can use it to identify the exact part form, material and verification method expected for this aerospace application.

What are the key requirements of oSIST prEN 2328:2026?

The standard ties the washer to a defined shape, material, surface condition, plating and acceptance checks. In practice, that means the finished part has to match the geometry, coating and inspection criteria before it can be used or delivered.

• Clause 4.1 says the configuration shall follow Figure 1, and the dimensions and masses shall follow Table 1. The dimensions apply after cadmium plating, so suppliers must check the finished part, not the bare blank.
• Clause 4.2 sets the surface roughness at Ramax = 3.2 µm before cadmium plating. This gives a controlled starting surface for plating and helps avoid quality variation caused by rough base material.
• Clause 4.3 requires carbon steel CR2 according to ISO 3574, with a minimum strength of 370 MPa. For procurement and manufacturing, this fixes the base material and removes guesswork about alternative steels.
• Clause 4.4 requires cadmium plating according to EN 2133 with a thickness of 10 µm to 20 µm. That matters because the coating is part of the defined product condition and affects corrosion resistance and final dimensions.
• Clause 5 gives the designation system, with the example WASHER TAB EN2328-08. The diameter code links the designation to the size in Table 1, which helps ordering, traceability and inventory control.
• Clause 6 requires the manufacturer’s mark plus the identity block on both the washer and its packaging, using a method chosen by the manufacturer. The marking should be indelible where possible and must not harm the washer’s characteristics, so identification must not compromise function.
• Clause 7.1 requires visual inspection for burrs, scratches and cracks, with sample quantities linked to delivered quantity. This gives a straightforward receiving and production check for surface defects.
• Clause 7.2 requires a bend test on 0.1% of washers, minimum three parts, after folding the locking tabs 90° and straightening them twice. The parts must remain free from visible cracks, which verifies that the tabs can be formed in service without failing.
• Clause 8 requires an approved aerospace production organization and a quality management system such as EN 9100 or an equivalent. It also points to a qualification procedure such as EN 9133, so manufacturers need documented control of production and qualification.

What changed in oSIST prEN 2328:2026 from the previous edition?

oSIST prEN 2328:2026 supersedes EN 2328:2006. The significant technical change stated in the document is the introduction of informative Annex A on the bending test and an installation example.

Which standards are used with oSIST prEN 2328:2026?

oSIST prEN 2328:2026 cites two normative references in the text:

• EN 2133 - defines cadmium plating for steels and related alloys, and is used here for the required cadmium coating on the washer.
• ISO 3574 - provides the material specification for cold-reduced carbon steel sheet of commercial and drawing qualities, which supports the CR2 base material requirement.

The document also points to related aerospace quality documents:

• EN 9100 - given as an example of an acceptable aerospace quality management system.
• EN 9133 - given as an example of an aerospace qualification procedure for standard products.

What does the oSIST prEN 2328:2026 document contain?

The document contains one figure, two main requirement tables and an informative annex. Figure 1 shows the washer configuration, including the identified features used to define the part shape.

Table 1 sets out the size codes together with the associated dimensions and masses, and Table 2 defines the number of parts to inspect for appearance checks based on delivered quantity. The text also includes the designation format, marking rules, the visual inspection method, and the bend test method.

Annex A adds a bending test and an installation example, which is useful for production setup, qualification and understanding how the tab washer is intended to be fitted in service.