An intravascular guide wire having at least two core materials joined together. There is a wire core having a proximal core section with a proximal end and a distal end and a distal core section with a proximal end and a distal end. The distal end of the proximal core section and the proximal end of the distal core section are formed into complementary shapes, and then placed into a flexible sleeve in opposing directions. Inside the flexible sleeve, the complementary shaped ends are joined together through bonding, welding, brazing, cementing, or soldering. The flexible sleeve can be either a stretched coil or a polyimide sleeve, each with an outer diameter similar to the outer diameter of the core wire, therefore the guide wire does not require additional grinding to reduce the outer diameter of the joined section.