Abstract: A cutting apparatus for making circular or circular arc-like cuts in a sheet of material such as paper, cloth, leather, plastic, rubber and the like. A substantially planar base is provided to receivably support said sheet and a hinged apertured clamping plate is lowered over the supported sheet to secure it against movement during the cutting operation which takes place through the aperture. An arcuate arm is secured to the base and an elongated portion of the arm positions an internally-threaded vertically-oriented boss above the aperture. An externally-threaded member is operably received within the boss and includes an adjustment disc for turning said member to raise or lower same within said boss. A blade-positioning shaft is received within a vertically-oriented central bore in the member and includes a shoulder to secure the shaft for vertical movement with the member. The lower distal end of the shaft includes a threaded pin for being slideably received within a radius selecting slot of the blade.