The Jacobs 36B Plain bearing chuck is the world's most widely used for portable, bench, or floor mounted power tools. This Industrial grade quality chuck, with fully hardened and ground working components, offers exceptionally high accuracy, gripping power and durability. The chuck capacity is from 0.188-Inch to 0.800-Inch (5.0 Millimeter to 20.3 Millimeter) with 5/8-16 Threaded mount. T.I.R. 0.004-Inch maximum at half capacity. Like all of Jacobs Plain Bearing Chucks, each Jacobs 36B Plain bearing chuck is 100-Percent inspected for performance and precision, and includes a one year factory warranty