| 摘要 |
PROBLEM TO BE SOLVED: To stabilize a shape of a seat by inserting a ball into a ball house in a tip body, conducting first beating to preliminarily form a seat, further conducting second beating to form the seat, and then caulking an end of the tip to form a caulked part. SOLUTION: A ball 19 is inserted into a ball house in a tip body 10, first beating is conducted once to preliminarily form a seat 17, and further second beating is conducted once or more to complete the seat 17. Thereafter, a front end of the body 10 is caulked to form a caulked part 18. A spring-back occurs at the seat 17 formed by the first beating. However, this spring-back is almost disappeared by the second beating. Since a shape of the seat 17 formed in this manner is stabilized, when the end of the body 10 is caulked to form a caulked part 18, the ball 19 can be stably supported, and hence a writing fault scarcely occurs. |
