Phillips flathead machine screw, 10-32 stainless steel. Fine thread.

Designed to go through a hole or nut that is pre-tapped to form a mating thread for the screw. This style head is used in applications where protrusion of the fastener above the mating surface is unacceptable. Phillips drive is the most common drive used and is designed to "camout" when the screw reaches optimum tightness, thus preventing damage to the screw head. Made from austenitic stainless steels. It contains chromium creating an invisible surface film that resists oxidation making the metal corrosion resistant. If the surface layer is damaged, it rebuilds itself in the presence of oxygen.