Cross-Recess Head Zinc plated and passivated hardened steel Self-drilling screws offer all the advantages associated with standard self-tapping screws but are capable of drilling their own pilot holes into sheet metal up to 5mm in thickness.,Self-drilling screws should always be installed using a power-driver and are therefore particularly suited to fast production environments.,They can be used in light and heavy gauge sheet metals, soft plastics etc, and are ideal for applications in heating and air conditioning, metal and fibreglass fabrication industries. To DIN7504