Self-drilling expansion fastener and method of forming same

A method of integrally forming a self-drilling expansion fastener from a sheet metal material through a series of punching and stamping, comprising the following steps:

• obtaining a sheet metal material having dimensions required for forming the self-drilling expansion fastener, and defining an expansion structure zone and a drill structure zone on the obtained sheet metal material;
• stamping the expansion structure zone at a specified location, which is defined as a thread forming zone, to obtain threads having required dimensions;
• punching the expansion structure zone at a specified location, which is defined as a barrel body forming zone, to obtain a plurality of force-distributing bars;
• punching the drill structure zone at a predetermined location to obtain a required chip guard;
• punching the drill structure zone at a predetermined location to obtain a required drill;
• and
• stamping the thread forming zone and the barrel body forming zone to obtain required configurations for these two zones.