Hollow screw or bolt for releasably fastening components together has head whose internal profile allows tool to be inserted to unscrew it and is produced from semi-finished sheet metal product or plastic

摘要

The hollow screw or bolt for releasably fastening components together has a head (1) whose internal profile, e.g. a hexagon, allows a tool to be inserted to unscrew it. It is produced from a semi-finished sheet metal product, e.g. by internal high pressure forming, or for plastic, e.g. by injection moulding