Abstract: A large size barrel-shaped dent ball for removing dents in curved and tapered tubing having a diameter between 21/2 and 41/2 inches such as a tuba. The ball is constructed with a hardwood core and a steel band about the center portion of its length. An axial steel tube is also inserted in the hardwood core to facilitate use and removal of the ball from the tube. This composite structure reduces the overall weight so that the ball can be manipulated during use. A cable tool on which the dent ball can be strung between two metal impact balls is also presented. Reciprocation of the cable provides repeated impact of a metal impact ball against the barrel-shaped dent ball to drive the dent ball under and past the dent in a dent removal and tool retrieval direction.