D2 Ground Oversize Tool Steel Rectangle/Flat Bar is ground to a maximum surface finish of 40 Ra with tolerances of + 0.010" to + 0.015" on the thickness and the width. This material is produced from cross-rolled sheet or plate which produces a finer grain size and enhances the toughness of the material. Lastly, tool steel rectangle bar is 100% free of decarburization is completely spheroidized throughout.