Patent 7469721 was granted and assigned to Sumitomo Metal Industries on December, 2008 by the United States Patent and Trademark Office.
A thread protector for protecting threads of a pipe includes a body having female or male threads shaped for threaded engagement with male or female threads formed on a pin or box end of a pipe. An elastically flexible annular sealing projection extends from the body to a location where it will be elastically flexed by and in line contact with an end surface of the pipe when the threads of the protector are engaged with the threads of the pipe. The thread protector can protect the threads of a pipe against deposition of dirt and against rusting without application of grease.