DISK-SHAPED MAGNETIC RECORDING MEDIUM AND PRODUCTION THEREOF

PURPOSE:To obtain the magnetic recording medium having excellent electromagnetic exchange characteristics by changing the pressure distribution, polishing time or pressure distribution and polishing time of a polishing tape in the radial direction of the disk. CONSTITUTION:The disk 1 of the magnetic recording medium is pressed by a flange 2 is rotated at a constant speed. While the polishing tape 3 is fed at the constant speed, the polishing tape 3 and the disk 1 are pinched by rugged rubber 4 having the semispherical front ends. Pressers 4 are moved back and forth in the radial direction of the disk by the mechanism which is widened in spacing when the pressers 4 exist on the outer periphery of the disk 1 and is narrowed the nearer the inner periphery. The pressure is increased and the surface roughness decreases on the inner periphery of the disk. The pressure decreased and the surface roughness increases in the outer peripheral part. The polishing property increases and the surface roughness decreases when the moving speed of the pressers 4 is set lower the nearer the inner periphery. The gradient of the surface roughness is more efficiently created if the two methods are used in combination. The ratio of the square average roughness in the outermost and innermost peripheral tracks is specified to a 1.2 to 2.5 range to monotonously decrease the surface roughness.