Interior tray | A4 | WS 9255
Finishing Washer WS 9255, also known as a trim washer, in acid-proof stainless steel A4 is a high-quality product designed to combine durability and function. Manufactured from stainless steel to resist corrosion and wear, the washer is ideal for use in demanding environments. It functions as a flat washer but provides extra support for countersunk screws.
FIELD OF APPLICATION
The finishing washer is used as reinforcement when installing screws and bolts to distribute the load evenly. It is particularly useful in installations where strength and aesthetics are important. The advantage of using stainless steel is its long-lasting resistance to rust, making it suitable for both indoor and outdoor use.
Watch video: Which washer should you choose?
TECHNICAL SPECIFICATIONS
Product type: Finishing washer
Grade: A4 / AISI 316 acid-proof stainless steel
Strength class: Not applicable
Suitable for: Countersunk screw with 90° head angle
FREQUENTLY ASKED QUESTIONS (FAQ)
What is the primary function of a finishing washer (trim washer) according to WS 9255?
WS 9255 is a cupped washer specifically designed to be combined with countersunk screws in applications where the hole cannot or should not be countersunk:
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Enables neat mounting of countersunk screws: The washer's cupped, conical profile accommodates the angle of the screw head (90°) and allows a countersunk screw to sit perfectly flush inside the washer instead of protruding with sharp edges.
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Neat and professional finish: The curved, smooth outer contour provides a decorative and stylish impression on visible surfaces in interiors, panel assemblies, and vehicle interiors.
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Even pressure distribution on soft materials: The wide contact surface under the cup distributes clamping force over a larger area, preventing the screw head from pulling through or cracking sensitive materials such as wood, plastic, leather, textiles, or thin sheet metal.
Why is acid-proof stainless steel A4 (AISI 316) a good material choice for finishing washers?
Finishing and trim washers are often used in spaces where aesthetics and moisture resistance are equally important:
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Corrosion-resistant and hygienic: A4 steel (1.4401 / AISI 316) resists moisture, condensation, salt water, spills, and cleaning agents without discoloring, staining surrounding materials, or forming surface rust.
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Durable surface finish: Unlike chrome-plated or zinc-plated steel washers, there is no surface layer that can be scratched or flake off over time, ensuring the shiny finish is preserved.
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High dimensional stability: The washer remains rigid and does not deform when the screw is tightened, ensuring the recommended cupping maintains its precise fit against the screw head.
Which screw types are best combined with finishing washer WS 9255 and how are they installed?
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Correct screw type: Ideally combined with countersunk wood screws, countersunk machine screws (DIN 965 / DIN 7991), or oval countersunk screws (DIN 966) with a 90° head angle.
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Correct screw dimension: Choose the washer's inner diameter so that it exactly matches the screw's nominal thread size (e.g., M4, M5, or M6) so that the screw head rests evenly in the cup without play.
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Easy pressure mounting: No countersinking tool or recess is needed in the substrate. Simply place the washer over the drilled hole, insert the countersunk screw, and tighten.