Type 27 depressed center cutting blade. Thin .045 width. A60S grade for general purpose use. Special aluminum oxide grain. Hard bond for extremely long life. Fast, burr-free cutting. For use on all ferrous and/or non-ferrous metals (iron, steel, and welds). Size 4-1/2"D x .045"W x 7/8" bore. Maximum RPM 13,300.