Available in diameter sizes ranging from 0.562-1.375 in. and 16-42 mm with 2, 3, 4 x Dc, the new drill delivers maximum process reliability with simple and efficient chip removal, two coolant channels and polished flutes. Superior protection against friction is provided by the D3120 hardened and polished surfaces. This combination of surface hardness and improved coolant flow results in reduced wear on the drill surface.