New in original packaging . The BC 20MM 80 grit Boron Carbide Flex-Hone surface finishing and deburring tool is excellent for medium to high carbon steels and heat-treated steels to 50 Rc. It is also useful in titanium. The tool features a 2.50 in abrasive part and is designed for nominal bore sizes between 0.75 in and 0.787 in. Overall tool length is 8 inches long and has a twisted wire stem for use in any collet, chuck or similar holding device. 80 grit generally provides an Ra finish range of 45 - 64 Microinch (1.2 - 1.6 Micrometer).