| 摘要 |
In a core bit formed with a boring blade at a front end thereof and integrally formed with a mounting portion, at a rear end portion thereof, formed with a guide portion in a cylindrical shape mounted to a chuck portion formed at a concrete drill, a ring-like seal member forming a seal between the mounting portion and a side of the chuck portion is formed at the guide portion in the cylindrical shape of the core bit. <IMAGE> |
