Abstract: A method of blackening a magnetic shield for use in a color CRT (Cathode Ray Tube) is disclosed. A plurality of magnetic shield members are stacked with clamps inserted in their holes beforehand or with the intermediary of cut and raised portions or lugs thereof. Therefore, efficient work is promoted in relation to a blackening furnace and other facilities, work space, the number of steps of forming a blackening film, etc. In addition, oxygen flows evenly between the adjacent shield members, forming blackening films of high quality.

Abstract: In a method of manufacturing a clamp, an elastic band member is bent into a direction of an inner surface at a center position of the band member. The band member having the inner surface and an outer surface. The band member is bent into the direction of the inner surface at first bending portions having a first predetermined length from the center bending portion to form first extending portions. The band member is bent into a direction of the outer surface at second bending portions having a second predetermined length from the first bending portions in tip directions to form second extending portions. The band member is bent into the direction of the outer surface at third bending portions having a third predetermined length from the second bending portions in the tip directions to form third extending portions.