Self-drilling screw is a screw that can tap its own hole as it is driven into the material.  For hard substrates such as metal or hard plastics, the self-drilling ability is often created by cutting a gap in the continuity of the thread on the screw, generating a flute and cutting edge similar to those on a tap.  Thus, whereas a regular machine screw cannot tap its own hole in a metal substrate, a self-drilling one can (within reasonable limits of substrate hardness and depth).

Flat Head: The head of the screw is flat, allowing it to sit flush with the material surface. This is ideal for applications where a smooth, even finish is required.

Screw of union of all type of wood to plates and profiles of steel. • The fins of the drill bit allow to oversize the hole in the wood, avoiding 2 problems: 1. Perform annoying and expensive previous drills 2. The separation between wood and steel, being an incorrect and problematic assembly, both functionally and aesthetically. • With grooves under the head to be fully flush in the wood