Magnetic disk and substrate for magnetic disk

A magnetic disk that has a hole at a central portion of the magnetic disk,

• wherein the magnetic disk has
• a thickness of 0.60 mm or less,
• a radius denoted by R (mm),
• Total Indicated Reading (TIR)s measured on circles having different radial distances r1 (mm) and r2 (mm) on the magnetic disk denoted by TIR1 (μm) and TIR2 (μm), respectively, and
• an amount of radial variation ΔTIR for TIRs of 0.50 μm/mm or less in an outer circumferential region of the magnetic disk at which r/R is 0.70 to 0.99,
• where “r” is a radial distance (mm) on the magnetic disk that is measured from the center of the magnetic disk, TIR for a specific radial distance is the difference between the highest point and the lowest point at a circumference of the specific radial distance on a plane fitted to a main surface of the magnetic disk by least squares, and the ΔTIR is represented by |(TIR1−TIR2)/(r1−r2)|, which is an absolute value of a ratio of a difference (TIR1−TIR2) between the TIR1 and the TIR2 with respect to a difference (r1−r2) between the radial distance r1 of the magnetic disk and the radial distance r2 of the magnetic disk.