Self Drilling Screw

A self drilling screw is a tapping screw with a drill point that cuts its own hole in metal or plastic. It forms a thread as it is driven, so no pre-drilling is needed.

A self drilling screw drills its own hole and forms a thread in one step. It suits thin sheet metal, cladding and light fabrication. It often matches a Phillips or hex driver and can take a sealing washer under a flanged head.

A passivated finish removes free iron from the surface of stainless steel and helps the metal resist corrosion after machining. It is often applied to stainless steel screws that see outdoor or damp service. The finish leaves the surface clean and does not add a coating colour.

Self drilling screws are often made in steel, stainless steel 304, stainless steel 316 or stainless steel 410. Steel screws are usually plated for corrosion resistance. Stainless steel grades suit outdoor and corrosive exposure.

This is a general guide to checking this kind of part. It says nothing about any supplier's parts.

Ask for a certificate of conformance and a material certificate for stainless steel grades. On receipt, check the drill point, thread form and head drive. Confirm the screw length and diameter match the order.