A fluid conduit for a gas turbine engine includes a first fluid conduit attachable to a second fluid conduit and securable together with a lockable connector. The connector includes a first portion including external threads and a second portion receiving the first portion and including internal threads mating to the external threads of the first portion. The internal threads include lead threads defining a first thread interface with the external threads for starting attachment of the first portion to the second portion and locking threads defining a second thread interface for locking the first portion to the second portion.