PURPOSE: To easily judge whether printing inferiority is generated by the abrasion of a printing pin or other cause by forming first and second abrasion- resistant alloy members and a matrix material into a predetermined shape to constitute the printing pin.
CONSTITUTION: A first abrasion-resistant alloy member 2 is fixed to the leading end of a matrix material by a welding means or the like and the length thereof is set to an abrasion limit dimension L by grinding. A second abrasion-resistant alloy member 3 different in color from the member 2 is fixed to the leading end of the first abrasion-resistant alloy member by welding. The first and second abrasion-resistant alloy members 2,3 are processed into a predetermined shape in a pair by grinding and, further, the matrix material 1 is processed by cutting to be finished so as to have a predetermined diameter. When the second abrasion-resistant alloy part 3 is abraded to be eliminated in the printing pin thus constitution, the printing pin becomes only the first abrasion-resistant alloy part 2 and the matrix material 1 and, therefore, it can be easily and visually judged that the printing pin arrives at an abrasion limit value.
Next Patent: COLOR THERMAL PRINTING METHOD