Assemblies that can be disposed in a subterranean bore and that can facilitate branch wellbore creation are described. An assembly can include threadedly coupled components having inner and outer sealing members in grooves. The sealing member can cooperate with the components to provide a pressure seal. The assembly can also include a venting member for equalizing pressure in a chamber defined by the coupled components. One of the components can be made from aluminum. At least part of that component can be coated with a coating material that is nonconductive.