Screw fastener for enamelled part

摘要

The enamelled item (1) has holes stamped to locate the screw fasteners. The holes are recessed in a dimpled pressing with the hole edge shaped to match the screw pitch and to provide a secure grip for the screw. A radial slit provides the start of the screw grip. The hole is first punched into the surface followed by the shaping press operation. The enamel coating is applied last. The metal screw fastener is secured into the shaped hole and grips the enamel via a pressure washer.