The Chuck Adaptor 19.05Mm X 1/2" X 20Unf Weldon Shank Tcac Is A Versatile Tool Accessory Designed To Convert Different Types Of Drill Bits Or Tools For Use With A Compatible Chuck. The 19.05Mm Diameter And 1/2" X 20Unf Thread Size Ensure A Secure Fit, While The Weldon Shank Provides A Strong, Rigid Connection For High-Torque Applications. It Is Typically Used In Machining, Drilling, Or Milling Operations, Allowing For Quick And Easy Tool Changes. The Tcac Label May Refer To A Specific Brand Or Series Within The Tool Adaptor Range.Size,1.5cm, 2.5cm,3cm.