| 摘要 |
PROBLEM TO BE SOLVED: To provide a frac ball capable of withstanding high water pressure and capable of increasing excavation work efficiency by decreasing damage caused to a crushing tool, and a cylindrical member for an excavation device comprising the same.SOLUTION: A frac ball is an approximately spherical body made of ceramics, and at least a part of the spherical body comprises an easy-to-crush part. In a cylindrical member for an excavation device, the frac ball 1 and a ball locking part 2 are arranged within a cylindrical body 3. |
