The Robert Sorby ultima cutters delivers great performance when hollowing, on both wet and dry timbers. This cutter has Titanium Nitride coating, giving it the sharpness of HSS, and the hardness of carbide. A diamond file or honing stone is used to hone the profile of the cutter around its perimeter.
As with all of the cutters, hone them often to maintain the edge and extend the life of the cutter.