Product description and applications: This bore brush set includes 8 cleaning brushes with different diameters. Brush diameters are 1(1/8), 1.0, 7/8, 3/4, 5/8, 1/2, 3/8, 1/4-inch (imperial unit) or 29, 26, 22, 19, 16, 13, 10, 7 mm (metric unit). The brush bristles are made with stainless-steel wires for heavy use and effective cleaning. The 1/4-inch shaft on the brush fits most power drills. They are commonly used in applications that include, but are not limited to: (1) cleaning the inside of pipes and tubes such as plumbing, HVAC, and automotive pipes, tubes, and fittings, (2) deburring and edge blending metal or plastic components, (3) cleaning and descaling industrial equipment to remove rust, scale, or other metal deposits, (4) preparing metal surfaces for welding and fabrication, (5) cleaning and maintenance of automotive and marine components to remove rust, corrosion, or other contaminants from engine parts, exhaust systems, boat props, etc. (6) surface preparation for applying coatings, and other various applications.