The stainless steel machine screw has a plain finish and a flat head with a drilled spanner drive. Stainless steel resists corrosion and may be magnetic. The drilled spanner drive, also called a snake eyes drive, has two holes opposite each other in the screw head to resist tampering by requiring a special driver to tighten or loosen the screw. The flat head is cone shaped for use in countersunk holes and has a flat top that fits flush with the mated surface.
Machine screws are threaded fasteners that are typically used with nuts or drilled and tapped (threaded) holes. Machine screws are available with a variety of head shapes, which determine how the screw interacts with the mating surface, and drive styles, which determine the type of driver required to install and remove the screw.