This item is a Sears Craftsman Vertical Milling Column, a vintage attachment used to convert a lathe into a small milling machine. Comes with Center Drills, Set of 5 1/2 2 Morse Taper (2MT) Collet Type: 2 Morse Taper (2MT) Round Collet. Size: Designed to hold tools or workpieces with a 1/2-inch diameter shank. Material: Typically made of high-grade tool steel that has been hardened and precision ground for accuracy. Features: Includes a 3/8-16 internal thread at the end for use with a drawbar. Designed for high concentricity and minimal runout, ensuring precise alignment during high-speed operations.