Screw, self drilling, tek, hex, black japan, GR 4.8, 5.5 x 30 mm, Fastbolt.

Tek screws, also known as self-drilling screws or self-tapping fasteners, are fairly common pieces of hardware. Aside from the drill tip of the screw, Tek screws look like standard screws. The tip of a Tek screw, known as the drill tip, includes a small carving piece at the end of the screw. Black Japan is a lacquer or varnish suitable for many substrates but known especially for its use on iron and steel. Its high bitumen content provides a protective finish that is durable and dries quickly.