These are made from a single piece of High Speed Steel, ground with a very fine edge. They are only suitable for non abrasive materials, but will give a superior finish in soft timbers. Generally HSS cutters are slightly less expensive than their TC grades, but can be more suitable for certain applications. Suitable for general grooving and rebating..........................D=1/4 inch|D=6.3 mm|C=16 mm|OL=48 mm|Shank Diameter=1/4 inch