Abstract: A portable adjustable washer cutter and improved sealing washer blank useful in telecommunications applications are described. The cutter comprises an essentially flat frame carrying a rotatable shaft and a platform placed opposite thereto for mounting a sealing washer blank in which a desired central opening is to be cut. An improved sealing washer blank having a small central opening and a small opening along its periphery can be easily mounted on the cutter by insertion of protruding members on the cutter through these openings. The sealing washer blank is cut by means of a blade mounted on a member attached to the bottom of the shaft. In a preferred embodiment, the sealing washer blank is provided with concentric annular ribs, the sealing washer blank being cut at a position between ribs.