Constant velocity joint boot

摘要

In a boot including a larger cylindrical portion having a thick-walled portion and a thin-walled portion continuing smoothly in the circumferential direction on the inner peripheral surface, a ring groove coming full circle on the outer peripheral surface of the larger cylindrical portion is formed. Since shrinkage at the thick-walled portion can be prevented by the ring groove, and the ring groove is formed smoothly over the entire thick-walled portion and the thin-walled portion, there exists no varying point at which a stress generated when fastening with a fastening member suddenly changes.