#8 x 5/8" tek screw / 1/4" hex washer head

Note:

Tek or Self-Drilling Screws, enable drilling without first creating a pilot hole.  These screws are usually used to join sheet metal panels together.  Tek screws are also used by body men to tack panels together for welding. A popular screw since it eliminates the need for drilling, and can be used multiple times.