304 stainless steel wire Cylinder Honing Ball Brushes included! This Silicon Carbide Cylinder Honing Ball Hone Brush is a precision-engineered abrasive tool designed for professional workshops and engine rebuild projects. With a 4.125" (105mm) bore diameter and 240 grit silicon carbide abrasive balls mounted on durable carbon steel stems, it delivers a consistent cross-hatch pattern, desired surface finish, and heavy burr removal with ease. The overall length of 10.6" and an 8mm shank make it compatible with virtually any rotating spindle, including hand drills, drill presses, hones, handheld tools, and CNC equipment. Ideal for bore deburring, edge rounding, surface finishing, and honing cylinder walls, engine bores, brake cylinders, hydraulic and pneumatic cylinders, and other metal surfaces. The flexible ball-tip design ensures self-centering action and uniform contact across the bore surface, making it a reliable choice for both professional mechanics and serious DIY enthusiasts tackling engine rebuilds or cylinder restoration work.