Abstract: Disclosed are systems and methods of beveling gripping holes of bowling balls. A method includes creating a bevel at an edge of a hole of the bowling ball by removing material from the bowling ball using a rotary tool equipped with a shaping bit that extends into the hole.

Abstract: Disclosed are systems and methods of beveling gripping holes of bowling balls. A method includes creating a bevel at an edge of a hole of the bowling ball by removing material from the bowling ball using a rotary tool equipped with a shaping bit that extends into the hole.

Abstract: A device for determining the placement of gripping holes with respect to the pin and/or the center of gravity and/or the mass bias of a bowling ball has a meridian plane indicator, a vertical axis plane indicator and a horizontal axis plane indicator. The meridian plane indicator has a scale which determines the distance between placements of finger holes and a thumb hole for bowling balls. The vertical axis plane indicator has a scale which determines the distance from the horizontal axis plane to the location of the positive axis point. The horizontal axis plane indicator has two scales; the first determines the distance between the meridian plane and the vertical axis plane about the surface of the ball along the horizontal axis plane, the second scale determines the angular displacement of the meridian plane and the vertical axis plane.