Method for producing hybrid driveshaft

This invention relates to a driveshaft of an automobile, more particularly to a hybrid driveshaft having a stem simply formed in one piece while the stem transmits a required driving torque and has high fundamental natural bending frequency to avoid a resonant critical vibration. This invention also relates to a method for producing the hybrid driveshaft. A hybrid shaft adapted to be used as a drive shaft of an automobile transmission system comprises a unitary cylindrical hybrid stem formed from a metal tube and a composite material layer adhered to the metal tube. The metal tube provides torque-transmission strength to the hybrid shaft while the composite material layer increases a specific modulus of the hybrid shaft. The hybrid shaft is produced by stacking a composite material layer on a metal tube, putting a thermal shrinkage tube on the composite material layer, and co-curing the metal tube and the composite material layer while exerting a longitudinal compression force on the metal tube to prevent it from being thermally expanded.