Union Butterfield 4533 High-Speed Steel Chucking Reamer, Straight Flute, Round Shank, Uncoated (Bright), 1/4 inch Straight flute for general-purpose reaming of uninterrupted cuts in through holes and blind holes High-speed steel is compatible with a variety of materials Uncoated (bright) tools have no additional surface treatment or coating, suitable for general-purpose applications 45-degree bevel at the cutting tip facilitates entry to a pre-drilled hole Round shank aids accurate centering; designed to be held in a chuck or collet for high-torque applications