An inset panel fastener is provided primarily for honeycomb substrates, such as those employed in the aircraft industry. The inset panel fastener includes a plastic body portion and a metal female threaded nut positioned within the body. The body includes a cylindrical barrel shape having a top and a bottom. A bore extends through the body from the top to form an opening for receipt of a male fastener. The metal nut has locking threads and is positioned in body's bore at the body's top proximal extremity. The body further includes non-locking plastic female threads integrally formed into said body's bore. The plastic female threads have the same diameter as the metal threads and are immediately adjacent to the metal threads so as to form continuous threads for permitting receipt of a male threaded fastener. The metal female threads are locking threads to provide a locking action for locking a male fastener to the inset panel fastener. Meanwhile, the plastic female threads provide primary load bearing capabilities for the inset panel fastener.