| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a ball for a ball-point pen improving leaching of ink due to the ball while suppressing abrasion of receiving seat in a socket of a pen point to suppress sink of the ball, and capable of also improving a writing feeling on a greasy surface. <P>SOLUTION: A plurality of holes 10 are provided to a surface 100 of the ball. The surface 100 of the ball comprises the holes 10 and a flat part 11 having no holes 10 and the flat part 11 is constituted of a smooth mirror surface. The long diameter (d) of the opening part of each hole 10 is below 10 μm. Ra showing the smoothness of the flat part 11 of the surface 100 of the ball is not more than 0.01 μm, Ry is not more than 0.08 μm and Rz is not more than 0.06 μm. The boundary of the hole 10 and the flat part 11 has an almost curved shape. <P>COPYRIGHT: (C)2003,JPO |
