Each one of a pair of pivot arms is pivoted at one end to a stationary support, the pivots being in vertically spaced relation. The free end of each arm carries a driven shaft journaled therein. The shafts are free floating and are disposed in vertically spaced relation with their axes in a common vertical plane. Each shaft carries a chamfering tool and a guide roller therefor arranged in close proximity. Biasing means yieldingly urges the free ends of the pivot arms towards each other so that their respective guide rollers and tools forcibly engage the top and bottom faces of a workpiece passed therebetween. The shafts are driven from a single motor common thereto, using pulley and elastic belt drive connections. A similar arrangement of pivot arms carries means for applying liquid stain to the surfaces chamfered by the tools.