The 18-8 stainless steel vented machine screw has a plain finish and a flat head with a Phillips drive. The 18-8 stainless steel material provides strength and offers good corrosion resistance in many environments. The material may be slightly magnetic. 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 fastener. The flat head is cone shaped for use in countersunk holes and has a flat top that fits flush with the mated surface. The screw has been drilled through its length to allow liquid and gas to vent from the bottom of a blind tapped hole, and is often used in vacuum systems.
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.
