PURPOSE: To prevent the pattern of a core head from deforming by punching a core expansion base material after cutting the pattern, making holes for a pad, and then bending the material.

CONSTITUTION: In the 1st stage, a pattern D of lines, characters, etc., are carved in an anticorrosive metallic plate body 2 and in the 2nd stage, a core expansion base material 3 is punched and holes H for loosely fitting a nose pad to a holder box are formed. In the 4th stage, the material is bent in a core shape. In the 2nd stage, only the leg parts 3a and 3b of the nose pad core are punched and after the 4th stage for the bending work, it may be separated into individual cores. In the 1st and 2nd stages, a press die and a punching die are changed to produce many kinds of base materials, and the pattern is clearer than that manufactured by the striking of a header.