Premium Build The rack screws are constructed with high-grade carbon steel to prevent stripping. Then coated with matte-black zinc chromate plating that is resistant to corrosion. Smart Design Each rack screw features a Phillips truss-head design with self-guiding pilot points. Includes pre-installed nylon washers to prevent scratching rack equipment. Accessories Included All rack screw sets include washers and a plastic jar. M5 and M6 sizes also include cage nuts. Rack shelves contain four pieces of 10-32 screws, washers, and cage nut set.