To fit 112020 and 112220 Planes 9. 1/2G and 220G. (old style) Cutter Size. 1.5/8in Replacement irons (blades) for Stanley block and specialist planes. Made from chrome carbon steel which has excellent edge retention characteristics and allows a razor sharp edge to be honed. All cutters are fine rotary ground to give a flat surface that is easier to sharpen. G : Denotes suitable for old style planes.