Black Finishing Cup Washers M3–M8 — A4 Marine Stainless

Why choose these black finishing cup washers

These countersunk cup washers combine a decorative chemical-black finish with the corrosion resistance of A4 marine grade stainless steel — ideal where you want the screw head to sit flush within a clean, dark-finished seat. The cupped profile spreads load around the countersunk fixing while concealing the bore, giving a tidy professional finish on cabinetry, marine trim, signage and outdoor joinery.

Sizes available

Stocked in five common metric bore sizes to suit standard countersunk machine screws and woodscrews: M3, M4, M5, M6 and M8. Each washer is precision pressed from A4 (316) stainless steel and chemically blackened for an even matte finish that resists chipping and weathering.

Pack options

Choose a single washer sample, a pack of 10 for small jobs, or a pack of 20 for larger installations. Mixed sizes can be ordered in the same checkout to qualify for free UK delivery on orders over £20.

Typical uses

Boat fit-outs and cabin joinery, outdoor furniture, dark-finished kitchen and wardrobe handles, signage, security-screw concealment, audio and AV brackets, electrical face-plate trims, and any application where a stainless steel washer is needed but a bright finish would clash with black hardware.

How to fit

Drill or counterbore so the cup sits flush with the surface, drop the washer in place, then drive a matching countersunk-head screw through the bore. The cup profile centres the screw automatically and provides a finished seat that hides any minor over-drilling. Pair with black A4 stainless socket or countersunk screws for a fully colour-matched fixing.

Delivery

Same-day dispatch on orders placed before 2pm — free UK delivery on orders over £20.