Abstract: A damped boring bar assembly for damping the vibrations encountered during the high-speed boring of titanium, zirconium, and their alloys and the like, as well as steel and other metals, especially when the overhang, or ratio of the diameter to depth of the bored hole, is very small. The boring bar assembly has a weighted damper body contained within a hollow elongated case, the tool-holding end of which is closed and incorporates a shaped inner face with a frictional sliding surface. The damper body also has a frictionally slidable element which, with the damper body, holds a resilient element in compression in an internal cavity. The frictionally slidable element has a shaped face having a frictional surface thereon which engages the frictional surface of the inner face of the elongated case during vibration. The damping mechanism can be adjusted to handle different machining conditions.