| 摘要 |
PURPOSE:To obtain the titled wire excellent in the toughness and wear resistance by hardening a wire material with the permeation of carbon thereinto in a specified condition. CONSTITUTION:A wire 1 is hardened to the core in the segment 0.3-10mm., preferably 1-10mm. from the printing side tip face thereof while reduced to less than 40% as large as the radius thereof in the radial thickness of the hardened layer on the rear end side from this segment. Thus, even when the tip 13 of the wire 1 is ground off by 0.05-0.2mm., the hardened layer 12 is left on the entire tip face of the wire 1 thereby preventing eccentric wear of the tip face while supressing wear at the main guide section. |
