An anchoring tool anchors a tubing string within a surrounding well casing against rotation in either clockwise or counter clockwise directions. The tool includes a tubular housing for connection in line with the tubing string. A fixed jaw is fixedly mounted on the tubular housing and a floating jaw is supported for full rotation about the tubular housing past the fixed jaw. When the floating jaw engages the well casing, the overall diameter of the tool is varied as the fixed jaw is rotated with the tubing string relative to the floating jaw and the surrounding well casing. The tool can be used for anchoring the tubing string to the well casing in either direction while the tool remains down hole in the welt casing due to the floating jaw being rotatable past the fixed jaw.
