This key stock is a stock of square cold-drawn steel that is used to produce machine keys. For use with up to a 15/16-inch diameter shaft, the stock measures 12 length x 1/4 width x 1/4 height in inches. This oversize key stock has a length tolerance of -0.125 inches and a width and height tolerance of +0.002 inches. Made out of carbon steel, this key stock has a minimum hardness of 50 on the Rockwell B scale. This product has a plain finish.