Abstract: The present invention is a method and apparatus for centering a belt-shaped material. A conveying direction leading end portion and a conveying direction trailing end portion of triangular portions of the belt-shaped material are displaced in advance in directions opposite directions in which the conveying direction leading end portion and the conveying direction trailing end portion of the belt-shaped material are displaced when applied onto a forming drum. Centering of a constant-width portion of the belt-shaped material is carried out as follows. A width of the constant-width portion of the belt-shaped material is measured while the belt-shaped material is conveyed. In accordance with the measured width, a distance between a pair of guide portions which are disposed so as to be movable in a widthwise direction of the belt-shaped material is adjusted. The belt-shaped material is passed through a space between the adjusted guide portions.

Abstract: A waterproof nut which may be used, for example, inside a water storage tank, is constituted by a metallic nut body having the outer periphery coated with a synthetic resin layer which also covers both the front and rear surfaces of the nut body. The resin layer which covers the rear surface of the nut body includes a cap-shaped portion for accommodating the free end of a bolt which is screwed into the nut body in such a manner that the free end projects from the rear surface of the nut body, whereby water is prevented from entering the nut body.

Abstract: A waterproof nut which may be used, for example, inside a water storage tank, is constituted by a metallic nut body having the outer periphery coated with a synthetic resin layer which also covers both the front and rear surfaces of the nut body. The resin layer which covers the rear surface of the nut body includes a cap-shaped portion for accommodating the free end of a bolt which is screwed into the nut body in such a manner that the free end projects from the rear surface of the nut body, whereby water is prevented from entering the nut body.