Patent ID: 7955179

Claim:
A boot for a universal joint comprising: a bellows portion in which three or more crest portions extending in a circumferential direction and root portions therebetween are alternately formed; a large-diameter attaching portion formed at one end of the bellows portion; and a small-diameter attaching portion formed at the other end of said bellows portion, at least one of a rising wall closest to the large-diameter attaching portion in said bellows portion and a rising wall closest to the small-diameter attaching portion being formed thinner than the other portions in said bellows portion, an angle of inclination of the rising wall at the small-diameter attaching portion side of the crest portion closest to the large-diameter attaching portion being formed larger than an angle of inclination of the adjacent rising wall at the small-diameter attaching portion side, and an angle of inclination of the rising wall at the large-diameter attaching portion side of the crest portion closest to the small-diameter attaching portion being formed larger than an angle of inclination of the adjacent rising wall at the large-diameter attaching portion side.