Osborn 00032125SP 32125Sp Abrasive Cup Brush, Silicon Carbide, 6000 Maximum Rpm, 4" Applications: Engine Blocks, Cylinder Heads, Exhaust Manifolds, Transmission Housings, Water Pumps and Intake Manifolds, Bulk Heads, Wing Spars Applications: Engine Housings and Components, Hydraulic Valve Bodies, Machine Components, Housing, Gears and Castings Applications: Log home chinking and cleaning