Made of alloy in tone. Use for Hydraulic Tube Expander. For use with Soft Copper, Steel, Aluminum, and Brass tubes The special cone eccentric revolution allows the internal opening gradually regular flare without effort. ing tube from sliding down. keep the flare face smooth, and uniform without scratching. Eccentric cone will be rebound automatically after the work is finished, make the idle top head in revolution again for 1-2 times and have the flare face in friction to make it prettier.