Custom made durable rubber O-ring/small silicone washer/gaskets

A small rubber washer molded in silicone provides a flat annular contact surface around an opening. In a compact joint, that geometry differs from an O-ring with a rounded cross section, even when the outside dimensions appear similar. This custom product can be developed around the actual seat and the space available when the joint closes.

The central opening should remain clear of the mating feature, while the surrounding face needs enough supported area to make the intended contact. For a recessed installation, compare the washer thickness with the depth of the seat. A small change in either dimension can alter how much compression the assembly applies.

Handle the part without stretching its bore around a sharp projection. Place it flat and keep it centered as the adjoining component is fitted. The precise silicone compound should suit the medium and temperature at the joint. When replacing an existing seal, match its working cross section rather than choosing a ring solely by diameter or by the general name used for the component.

Material options

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

Hardness selection

Silicone: 20–80 Shore A. A small change in either dimension can alter how much compression the assembly applies.

Custom dimensions

In a compact joint, that geometry differs from an O-ring with a rounded cross section, even when the outside dimensions appear similar.

Fit & assembly

For a recessed installation, compare the washer thickness with the depth of the seat.

Use & inspection

The central opening should remain clear of the mating feature, while the surrounding face needs enough supported area to make the intended contact.

Photos illustrate structure or material only. In a compact joint, that geometry differs from an O-ring with a rounded cross section, even when the outside dimensions appear similar. ETOL directly manufactures custom-shaped silicone and rubber parts to your requirements.