[P-6] Surface Properties of Sintered Tungsten Carbide with Ultra-Fine Grains in Cutting by Diamond-Coated Ball-End Tools 〇Tetsuo Samukawa1, Kazuo Shiramizu1, Haruhiko Suwa1 (1.Setsunan University) Keywords:Machining、Sintered tungsten carbide、Diamond-coated ball end tools、Surface properties、Cutting condition