These are nice orings and are slightly thicker than bulk orings of the same size. For this reason they do seal very nice. If you are still having sealing problems with this oring, try cleaning up the contact areas with some 400 grit wet sanding paper. This will leave a very nice burr free sealing surface. Wipe the area Dry and allow oxygen to get to the fresh metal to renew the stainless properties of the metal._x000D_