Suitable for a wide range of applications such as engraving, grooving, rebating and shallow mortising. Use on softwoods, hardwoods, MDF, plywood and chipboard. All cutters have a bottom cut feature. ...........................D=5/16 inch|D=7.9 mm|C=1 inch|C=25.4 mm|OL=68.4 mm|Shank Diameter=1/4 inch