FASTENING SCREW AND FASTENING SYSTEM.

摘要

This invention relates to the fastening of material to thin metal structures. It will be convenient to hereinafter describe the invention with particular reference to the fixing of roofing material to battens of thin maerial with section, but the invention has wider application. The invention is concerned with fastening systems of the foregoing kind and is also concerned with a fastening screw for use in such a system.