Abstract: The present invention is for a method of lap joining two tubular members and then hydroforming the tubular assembly. An insert end of the first tubular member is inserted into a receiver end of the second tubular member to form a lap joint. A filler metal ring is placed about the outer periphery of the insert end so that it is adjacent the opening of the receiver end of the second tubular member. Heat is applied to braze or solder the lap joint, forming a tubular assembly. The tubular assembly is then hydroformed during which time a supplementary mechanical lock may be formed in the lap joint.