There is a choice of solid carbide, suitable for diameters from 3.17 mm to 25.4 mm, or high speed steel (HSS) blade, suitable for 1 mm to 50.8 mm diameter. The solid carbide tool can be used on heavy burrs at elevated cutting speeds that are at least three times greater than the HSS version. Tough and exotic materials, as well as non-ferrous, can be machined and due to the durability of the carbide and the TiN coating, tool life should be some five-times greater than the HSS version. There are two styles of HSS and carbide blade, with B catering for both front and rear cutting, while R is used for applications requiring only rear or back chamfering. The tool comprise an extended blade, having either one or two cutting edges, that are located via a dovetail in the holder. The dovetail, which also acts as a fulcrum, enables the cutting blade to become a flexible arm pivoting in the holder. Once the tool clears the back of the bore, the blade and cutting edge flexes back out of the holder and as the direction of feed is reversed, any rear burr or chamfer is cut as the tool begins to withdraw.