| 摘要 |
PROBLEM TO BE SOLVED: To enable the sure fastening of the conical pressure-applying opening of a fork leg portion to the inner ring of a roller bearing and further the easy disassembly of the fastening. SOLUTION: A countersunk head nut 1 has the first cylindrical outer peripheral surface portion 8 connected to the countersunk head 3 and the second cylindrical outer peripheral surface portion 9 connected to the first cylindrical outer peripheral surface portion 8 and having a smaller outer diameter d than the outer diameter of the first cylindrical outer peripheral surface portion 8. The first cylindrical outer peripheral surface portion 8 has such a surface as frictionally binding the first cylindrical outer peripheral surface portion 8 to the inside outline.final end portion 4b of the conical pressure-applying opening of a shaft rod portion. A countersunk head bolt 10 has an axially directed hole 13 having at least one interlocking element 13a which can be engaged with a screwdriver tool. |
