Color discrimination mask for color picture tube

摘要

A shadow mask is formed from a nickel-iron alloy containing 34% to 38% by weight of nickel. The nickel-iron alloy has a grain size number of not less than 10. The grain diameter of grains 12 in a cross-section in a direction perpendicular to the rolling direction 13 is not larger than 50 Ám. The average grain diameter in the elongation direction is not larger than 30 Ám. The shadow mask is provided with apertures by etching. The shadow mask is free from degradation of display characteristics due to degradation of the aperture configuration and capable of achieving a fine pitch by virtue of its high strength.