Why Stainless Steel Countersunk Washers From Fixabolt?
Our stainless steel countersunk washers are made for a reliable fit with standard metric countersunk screws. Solid cup washers are machined with a flat bearing face and a countersunk recess that matches the screw head, helping to clamp more evenly and protect the surface.
- Solid machined design for positive seating and good load distribution.
- Stainless steel construction for corrosion resistance in general outdoor, damp and many industrial environments.
- Made to suit standard countersunk screws, so assembly is straightforward on site.
- Neat, professional appearance around visible fixings and hardware.
- Trade friendly quantities with pack sizes suited to both maintenance and production use.
Use these stainless steel cup washers anywhere you want a tidy, reinforced countersunk fixing without having to countersink into the material itself.
What are Countersunk Cup Washers Used for?
Countersunk cup washers are used anywhere a countersunk screw needs to bear on a flat or oversized hole, or where the base material is too thin or too soft to countersink directly. The formed recess supports the screw head and the outer flange spreads the load.
Typical applications include:
- Furniture, shopfitting and interior joinery where visible fixings need a clean finish.
- Sheet metal panels, guards and covers where you cannot countersink the sheet.
- Timber and board materials that might split, crush or wear if countersunk directly.
- Electrical and mechanical enclosures, brackets and small fabrications.
- Marine and outdoor hardware when used with suitable stainless screws and fixings.
Compared with a flat washer, a solid countersunk washer keeps the screw head central and properly seated, improving appearance and reducing the risk of the screw pulling through softer materials.
Standards and Materials
Many metric solid countersunk washers are manufactured to the French standard NF E 27-619, which defines key dimensions such as internal diameter, outer diameter, overall height and countersink geometry for sizes typically from M3 up to around M12. Exact dimensions will vary slightly by manufacturer.
Typical material options in the market include:
A1 stainless steel (303) for general indoor and outdoor use.
A4 stainless steel (316) for marine environments, offering improved resistance to chlorides.
Stainless steel cup washers from Fixabolt focus on corrosion resistant grades suitable for use with stainless countersunk screws, so you can match materials and avoid issues where possible.
How to Choose the Right Countersunk Washer
When selecting countersunk washers or solid cup washers, it is important to match the washer to the screw and the job:
Match the thread size
Choose the washer to suit the screw size (for example M3, M4, M5, M6, M8, M10). The internal diameter is made to clear the screw shank for that size.
Check the countersink angle
Metric solid countersunk washers are typically made with a 90 degree countersink to suit standard metric countersunk screws. If you are using screws with a different head angle (for example some imperial 82 degree patterns), you will need matching washers.
Consider the Outer Diameter and Height
A larger outer diameter gives more bearing area to spread the load over softer materials, while the washer height controls how prominent the cup sits above the surface. Check OD and height against your available space and the look you want.
Pick the Right Stainless Grade
Use A1 stainless for most dry indoor and standard outdoor jobs, and A4 / 316 stainless for marine or chemically exposed environments, or where maximum corrosion resistance is required.
Trade supply and support
Fixabolt is set up for trade and DIY customers who want straightforward stainless fixings without the hassle. Order stainless steel countersunk washers in bulk, suitable for anything from one off repairs to production work.
Trade friendly quantities to reduce waste on site.
Reliable UK delivery to site or the office
Consistent specification so repeat orders match your existing assemblies.
