The 18-8 stainless steel thread cutting screw has a plain finish a Type F point style and an 82-degree flat undercut head with a Phillips drive The type F point is suitable for heavy gauge sheet metal aluminum cast iron brass and plastic The screw has machine screw threads that taper down to a blunt point with multiple cutting edges and chip cavities The 18-8 stainless steel material provides strength and offers good corrosion resistance in many environments The material may be slightly magnetic The flat undercut head has a flat top with an 82-degree cone-shaped bearing surface and is undercut to a lower head height for use in shallow countersunk holes The Phillips drive has an x-shaped slot that accepts a Phillips driver and is designed to allow the driver to slip out of the head to help prevent over-tightening and damage to the thread or fastenerThread cutting and thread rolling screws two types of self-tapping screws are threaded fasteners that create a mating thread in the wall of a hole The two screws differ from each other in the way that they create the threads Thread cutting screws cut the wall of the hole to create the thread creating material chips that need to be cleared away from the hole to prevent clogging Thread rolling screws also called thread forming screws do not remove material but instead press against the wall of the hole to displace the material and form the threads