| 摘要 |
<p>PURPOSE:To reinforce the ball hitting portion of a metallic bat main body by fitting a thin-walled pipe of hard metal around the outside of the ball hitting portion, and forming the pipe on the same plane as the main body by means of swaging. CONSTITUTION:A thin-walled pipe 2 made of titanium alloy is fitted around the ball hitting portion 1a of a metallic bat main body 1 made of aluminium alloy and its outside is swaged so that the pipe 2 is formed on the same plane as the metallic bat main body 1.</p> |
