A
shadow mask blank of Fe-Ni
alloy which exhibits excellent uniformity of
diameter of apertures formed by perforation with
etching for the passage of
electron beams, consisting of 34-38% Ni, 0.05-0.5% Mn, 4-20 ppm S, and the balance Fe and no more than specified limits of C, Si, Al, and P, with MnS inclusions 50-1,000 nm in
diameter dispersed at the density of at least 1,500 / mm2 or simply with etched holes 0.5-10 mum in
diameter emerging at the density of at least 2,000 / mm2 when the blank is immersed in a 3%
nitric acid-ethyl
alcohol solution at 20° C. for 30 seconds. A method of manufacturing the blank comprises hot rolling of a slab of the Fe-Ni
alloy, cooling, recrystallization annealing, cold rolling, etc. under controlled conditions: e.g., hot rolling the slab at 950-1,250° C. to 2-6 mm thick, cooling the stock in the range of 900-700° C. at the rate of 0.5° C. / second, continuously passing the stock through a
heating furnace at 850-1,100° C. for recrystallization annealing to adjust the
mean diameter of the recrystallized grains to 5-30 mum, and performing the cold rolling before the final recrystallization annealing at a
reduction ratio of 50-85% and the final cold rolling at a
reduction ratio of 10-40%.