摘要 |
PROBLEM TO BE SOLVED: To offer a lead core for writing instruments, draftsman's outfit and/or drawing tools, of which color particles do not break (peel) off and at the same time has visually identifiable information corresponding to the type of the lead core being used. SOLUTION: The lead core of this invention for writing instruments, draftsman's outfit and/or drawing tools has its surface covered with at least one coating and/or at least one partial coating. Further this coating carries the following identifications as its specific information; manufacturer identification mark, hardness identification mark, quality description and lead core size identification mark, etc. COPYRIGHT: (C)2006,JPO&NCIPI
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