Abstract: An apparatus for cutting workpieces adapted to engage the workpiece in at least four points of surface engagement. The apparatus has a clamping mechanism designed to be fastened to the workpiece. The clamping mechanism has a tool unit attached which includes adjustment means for displacing the tool unit relative to the clamping mechanism towards or away from the workpiece. The clamping mechanism has a frame element and arms extending from the clamping mechanism. Each of the four arms includes a bearing wheel. Each of the wheels may be used to engage a workpiece to retain its position while it is being cut.