Abstract: A cutter assembly for installation on the rotary discs of a concrete finishing/stripper machine includes a base member for mounting on the rotary disc of a machine, a cutter member carried on the base member having a plurality of interchangeable cutting edges selectively presentable to a cutting position, a guide channel for constraining the cutter element for movement relative to the base member between first and second positions, and a coil spring for urging the cutter member toward a first of the positions while permitting movement of the cutter element along a path away from the first position and toward a deflected position in response to forces applied to the cutter element caused by obstructions on the surface being finished. The compression or pre-load on the coil spring is adjustable for varying conditions. The entire cutter assembly is readily mountable onto the bottom of the rotating disc and channels thereof by wedges, making set up of the machine quick and easy.