Abstract: A thread protector for the external threads of a pipe comprises two parts, an outer sleeve and an inner casing having spaced arcuate sections. The arcuate sections have threads thereon conforming to the pipe threads, a flange at their outer end having raised bosses around its inner periphery, and a shoulder around its other end. The outer sleeve is axially matable with the casing, having a lip at its outer end and a channel about its other end. The two parts are axially secured to the threaded pipe and locked thereon by interaction of the casing and sleeve so that the unit is removable from the threaded pipe only by unscrewing the same as a unit.

Abstract: A thermoplastic thread protector is provided for use in protecting internal threads of a pipe or coupling, the protector comprising a tapered shell having threads thereon and an outer flange which rest on the end of the pipe, and a tapered expansion ring designed to expand the shell into locking contact with the pipe, the shell and ring being interlocked through a rim around one end of the ring and a lip around the other end so that the protector must be unscrewed as a unit from the pipe.