Abstract: A blind bolt for fastening superposed construction materials with each other through insertion thereof into through holes formed in the construction materials, which blind bolt comprising a bolt section having a male screw, a flange portion formed at one end of the bolt body, and a tapered slanted surface extended from one end of the external peripheral surface of the flange portion to the male screw, a cylindrical spacer formed with a plurality of slits opened to one longitudinal end thereof, which spacer receiving the bolt body in such a manner that the slits are abutted against the flange portion, and a nut to be tightened by engaging with the male screw. With this construction above, as the bendable piece of the spacer is sandwiched between the inner surface of the holes in the construction materials and the flange of the bolt, even though the inner surface of the holes is mechanically deformed, the bendable piece is not severed, so that an extremely great tensile strength can be provided.

Abstract: A blind bolt comprising a headed bolt with a male screw at the side opposite its head having an external diameter which can be inserted into through-holes of architecture members to be tightened; a rotating washer made of a cylindrical member having an external diameter which can be inserted into the through-holes of architecture members, and having on both end surfaces slopes in parallel to each other each of which has a longitudinal diameter larger than that of the internal diameter of each of said architecture members; and a nut which is screwed to the male screw. Thus, the blind bolt can be inserted into through-holes of architecture members from one side and also can be nut-tightened from the same one side thereby tightening the architecture members.