a hybrid metal / composite spinner cone used in aircraft applications . the spinner cone has a metal outer shell which is bonded during the molding process to an inner structural member of thermoplastic composite . the metal shell imparts several desirable characteristics to the spinner cone such as impact resistance , erosion resistance , appearance , and supplying a lightning strike material to protect the composite structure . the thermoplastic composite has significant property advantages over metal or thermoset systems . the hybrid metal / composite spinner cone is manufactured using a ceramic mold which is less expensive and more readily available than a steel mold . the metal shell provides a barrier between the thermoplastic composite and the ceramic mold and allows the finished spinner cone to be easily released from the mold .