Lock Nut, yomwe imadziwikanso kuti mtedza, mtedza wotsekemera, mtedza wodziletsa, mtedza wokhazikika, mtedza wolimba wotsekemera, ndi mtedza womwe umatsutsa kumasuka pansi pakanjenjemera ndi makokedwe. Mtedza wonyezimira komanso mtedza womwe ulipo ndi wamtundu winawake pomwe gawo lina la mtedza limasokonekera kwambiri kuti litseke.