Abstract: A guard for a rotary cutting tool allows for automatic adjustment of the guard relative to the cutting disc and to a workpiece. Such an automatic adjustment allows a user to cut around substantially the entire circumference of a rounded workpiece, such as a pipe, without requiring alteration of the angle at which the tool is held, repositioning by the user, or repositioning or removal of the guard. The guard includes a bracket for mounting the guard to the rotary cutting tool, a hood mounted to the bracket and enclosing a portion of the cutting disc, and a spring for biasing one end of the hood into substantially continuous contact with the workpiece during operation of the rotary cutting tool.