Abstract: An apparatus and method are disclosed for reducing the oxygen concentration at the interface between a cutting tool and a relatively rotating metal workpiece. The apparatus comprises (a) a supporting means for holding the cutting tool in a predetermined position relative to the workpiece, and (b) means effective to direct a plurality of discrete flows of inert gas between the cutting tool and workpiece in a manner to substantially reduce the oxygen concentration in the zone to a predetermined level. The method comprises (a) directing a first stream of inert gas closely adjacent the interface, and (b) directing a second stream of inert gas to at least partially surround the first stream.