Abstract: An inertial guide and support particularly adapted for use with sabre saws, the inertial guide and support including a relatively heavy base providing sufficient inertia to hold the sabre saw blade against a workpiece during a portion of the stroke of the blade and also including apparatus located adjacent the workpiece for supporting and guiding the saw blade while permitting rocking of the blade relative to the workpiece whereby the cutting efficiency and workpiece thickness range of the sabre saw are increased while vibration and operator fatigue are reduced during operation of the sabre saw.