Hot-selling FKM NBR rubber seal O-ring/square rubber washers

Custom square rubber washers and O-ring configurations address different joint profiles. The required sealing shape should be established before choosing between FKM and NBR material options. A flat square washer and a round-section ring are not interchangeable simply because they cover a similar opening.

Review the actual seat and the direction in which the joint compresses the rubber. The seal should remain supported around its perimeter without blocking an intended passage. Corner details and thickness matter for the square form, while the ring profile requires its own retaining geometry. Evaluate the completed connection rather than the loose part alone.

Material selection should follow the medium, temperature, and contact duration in the application. Keep the selected version identified during replacement so a similar color does not lead to a compound substitution. Clean the mating surfaces and inspect for defects before fitting. If the old part was displaced or pinched, address the seat and closing arrangement instead of choosing another profile to fill the same space.

Material options

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

Hardness selection

Rubber: 30–90 Shore A. If the old part was displaced or pinched, address the seat and closing arrangement instead of choosing another profile to fill the same space.

Custom dimensions

A flat square washer and a round-section ring are not interchangeable simply because they cover a similar opening.

Fit & assembly

Review the actual seat and the direction in which the joint compresses the rubber.

Use & inspection

Clean the mating surfaces and inspect for defects before fitting.

Photos illustrate structure or material only. Corner details and thickness matter for the square form, while the ring profile requires its own retaining geometry. ETOL directly manufactures custom-shaped silicone and rubber parts to your requirements.