SQUARE ENDMILL MADE OF COATED CEMENTED CARBIDE WITH PERIPHERAL CUTTING EDGE HAVING SUPERIOR CHIPPING- RESISTANCE IN HIGH-SPEED CUTTING

摘要

PROBLEM TO BE SOLVED: To provide a square endmill made of coated cemented carbide with cutting edges having superior chipping-resistance in high-speed cutting. SOLUTION: A cylindrical blind hole is formed on the bottom surface of the hard metal body longitudinally and coaxially. A cylindrical tip made of a heavy tungsten-base cemented carbide is fit into the cylindrical blind hole. The hard metal body of cutting edges is constituted by sintered compact-powder of; Co: 8-10 wt.%, chromium carbide and/or vanadium carbide: 0.1-1.5 wt.%, if necessary composite carbide of Ta and Nb: 0.1-1.5 wt.%, and tungsten carbide: remainder. The cylindrical tip is constituted by sintered compressed-powder of; Co: 0.5-2 wt.% and tungsten carbide: remainder. The diameter of the cylindrical tip will be equivalent to 25-45% of the peripheral cutting edge diameter, and the length to 20-40% of the length of cutting edges.