Abstract: A thread protector for the external threads of pipes comprising a thread cap structure that is composed of plastic material and defines internal threads that are adapted to receive the externally threaded pin portion of a pipe. The outer extremity of the thread cap is formed to define a reduced diameter receptacle portion that receives a mating metal cap structure in such a manner that the thread cap and metal cap define a substantially contiguous annular outer surface. The metal cap is formed to define an annular body portion that defines a plurality of spaced apertures that are adapted to receive the plastic material of the thread cap to establish an interlocked relation between the plastic and metal cap structure. The metal cap defines a substantially planar circular end wall flange forming an opening through which an end wall portion of the plastic inner body protrudes.