High quality square NBR rubber washers/sealing gaskets

Square NBR rubber washers are custom sealing parts developed around a defined straight-sided interface. Their dimensions should match the usable contact area and allow the joint to close without drawing the rubber out of position. The center opening and corner profiles are part of the fit, not just the overall width.

Review the washer as the mating parts are secured. The rubber should stay flat and supported rather than slide toward a fastener or gather at a corner. An uneven closing gap can place different compression around the perimeter. Correct the joint alignment and follow its intended assembly method instead of relying on extra tightening to flatten a displaced gasket.

Select the NBR compound for the actual fluid and temperature exposure. Keep the seat clean and free of sharp defects before fitting. During replacement, inspect the old part for repeated corner damage or an uneven contact band. Those patterns can indicate an issue with the mating surface that a new washer of the same outline will not correct by itself.

Material options

NBR. Custom formulation and color for the intended contact conditions.

Hardness selection

Rubber: 30–90 Shore A. An uneven closing gap can place different compression around the perimeter.

Custom dimensions

The center opening and corner profiles are part of the fit, not just the overall width.

Fit & assembly

Correct the joint alignment and follow its intended assembly method instead of relying on extra tightening to flatten a displaced gasket.

Use & inspection

During replacement, inspect the old part for repeated corner damage or an uneven contact band.

Photos illustrate structure or material only. The center opening and corner profiles are part of the fit, not just the overall width. ETOL directly manufactures custom-shaped silicone and rubber parts to your requirements.