Custom silicone rubber round washers/NBR thin seal o-rings

Custom silicone rubber round washers and NBR thin ring seals address different sealing profiles. A flat washer presents broad faces, while an O-ring uses a rounded cross-section designed for its own seat. The required geometry and material should be identified together before selecting dimensions for the joint.

For a thin seal, handling and location are especially relevant. The part should fit without a twisted section or an edge pulled out of the intended contact area. A shallow seat can leave little room for folds, and a small change in thickness can affect the final closure. Evaluate the seal with the actual mating parts secured.

Silicone and NBR are separate material choices, each needing assessment for the medium and temperature involved. Keep the selected profile consistent during replacement. A similar outside diameter does not make a flat washer and a ring interchangeable. Clean the mating surfaces and inspect the old seal's contact pattern to identify any concentrated damage that could recur in the new part.

Material options

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

Hardness selection

Rubber: 30–90 Shore A. Silicone: 20–80 Shore A. Match compound firmness with the limited compression space in the shallow seat, checking the effect of small thickness changes on closure.

Custom dimensions

A flat washer presents broad faces, while an O-ring uses a rounded cross-section designed for its own seat.

Fit & assembly

The part should fit without a twisted section or an edge pulled out of the intended contact area.

Use & inspection

Clean the mating surfaces and inspect the old seal's contact pattern to identify any concentrated damage that could recur in the new part.

Photos illustrate structure or material only. The part should fit without a twisted section or an edge pulled out of the intended contact area. ETOL directly manufactures custom-shaped silicone and rubber parts to your requirements.