MUCH ingenuity has been devoted of late years to the problem of rapid and secure fastenings for sheet‐metal work, and numbers of devices have been evolved to replace the slower and more cumbersome traditional methods. A particularly interesting American development in this line takes the form of a threaded rivet of the type shown in fig. 1. The shank portion of this rivet is made somewhat thinner so that it can be upset by a suitable heading tool (hand or power). This heading tool transmits a pull on the threaded portion so that a bulge forms on the plain shank portion immediately above the threads and below the sheet or sheets to which the rivet is applied, and the pull on the threads is continued until the expanding metal seats itself firmly against the work to be fastened. The pull‐up stud of the heading tool is then removed from the threads, and the fixing is complete with the rivet threads clean, ready for the attachment of another member by means of a screw in the manner shown by fig. 2, giving at least six full threads for this purpose, no matter how thin the metal sheet.