Blind fastener and method of manufacture thereof

摘要

A blind bolt is of the type comprising a tubular shell 14 through which extends a stem 13 with an enlarged head 12 at one end which, in installation of the bolt, is pulled into the shell 14 to expand it and form a blind head. The stem 11 is provided with two opposed deformations 19 to prevent the shell falling off the stem before installation. Each deformation has a relatively shallow sloping profile with its higher end towards the shell, and the width of the deformation is a maximum at the bottom end of the slope and a minimum at its higher end. The deformations are formed by pinching up portions of the stem between two opposed dies, the shape of the bite between the dies being tapered in the direction along the stem.