nbsp; Tough and Corrosion Resistant: Phillips flat head screws are made of carbon steel, fixed and strong, resist corrosion for a long time. nbsp; Sizes Available: A variety of different screw sizes and lengths lets you find the right sizes for DIY projects and carpentry jobs. nbsp; Deep Thread Design: Deep Thread Design Wood Screws provide a good hold in different woods and synthetic materials, do not strip easily. Functional Home Tool: Flat head screw with good holding power, suitable for many carpentry and DIY jobs, fasteners for the furniture and cabinet industry. nbsp; Note: With functional stitch, please keep it out of the reach of children. Size: M4x20 (100PCS) | Color: Black Description: nbsp; High quality carbon steel provides strength in many environments. nbsp; Have enough stress bearing surface that can be screwed in more firmly. nbsp; Ease of Storage: Assorted screws and nuts in clear plastic bag for convenient use and storage. Easy and quick to get the size you want. nbsp; Ideal for use in confined areas where the head needs to be flush or below the surface. Widely used in home and office appliances, communication equipment, ship assembly and other machinery industries. -M4x20 = 4mm (Diameter) x 20mm (Length)