Steel Balls (鉄球 Tekkyū, lit. Iron Ball) are versatile weapons designed to facilitate Spin, featured in the 7th part of JoJo's Bizarre Adventure, Steel Ball Run. In two types, they belong mainly to Gyro Zeppeli and Wekapipo.
The Zeppeli Family's Steel Balls are polished, highly spherical balls of steel, about the size of a baseball or boule. They are grooved on opposite faces by two large hexagons, almost joined by lines crossing the balls between their corners.
These Steel Balls are designed to facilitate a powerful and versatile form of Spin focused on the manipulation of human or animal anatomy and various organ systems. They may be thrown far and with force, and maintain a lengthy, regular Spin, able even to boomerang after impact to the catch of their user.
They are used originally by the executioners serving the royal family of Naples, handed down through the generations of the Zeppeli Family. The techniques of the Steel Ball were developed with the aim of finding an honorable method of execution.
They have an effective range of around 20 to 30 meters.
Similar in size to the Zeppeli Family's Steel Balls, Wrecking Balls (レッキング・ボール(壊れゆく鉄球) Rekkingu Bōru (Kowareyuku Tekkyū)) are covered regularly by large dimples housing smaller balls, called satellites, which may separate in-flight to strike targets on their own. Even if these satellites do not quite meet their target, they produce airborne shockwaves which will induce an effect.
Wrecking Balls facilitate a form of Spin designed to induce temporary hemispatial neglect (左半身失調 Hidarihanmi Shitchō, lit. left-half ataxia); effectively killing all sensation in the left side of a target, explained as the cause of the ball's impact traveling through the body to cause a stroke or hemorrhage in the motor cortex.
The Wrecking Ball is primarily used by the guards serving the royal family of Naples.