| 摘要 |
A boring bit has a head, a blade assembly and a blade. The head has a mounting recess and two holding protrusions. The mounting recess is formed in the head and has a restricting surface and a threaded hole. The holding protrusions are formed on the restricting surface and each has two oblique restricting faces. The blade assembly is attached to the head and has a mounting base. The mounting base is mounted in the mounting recess and has an inner surface, a through hole and a guiding channel. The inner surface abuts with the restricting surface. The through hole is formed through the mounting base and aligns with the threaded hole. The guiding channel is formed in the mounting base, is mounted around the holding protrusions and has two abutting surfaces abutting the oblique restricting faces of the holding protrusions. The blade is detachably mounted on the blade assembly. |
