Technical Notes for 1/4":
Fact: Most standard VCR-Style gaskets are lapped or polished so that they can seal at 1/8th turn.
Problem: The lapping, polishing and individual packaging of these gaskets is costly, which makes the gaskets an expensive item for the user.
Solution: Non-lapped or non-polished gaskets will seal with more tightening than the standard products. Additionally there is no need to individually package these gaskets since their surface finishes are rougher than the standard ones. Scratches or minor imperfections are coined out of the surface of the gasket during the tightening process. When tightening past 1/8th turn is permissible, such as in testing applications, these gaskets can be a major cost saver.