Complete Assortment: 390pcs total, including #2-56, #4-40, and #6-32 UNC button-head socket cap screws with matching nuts. Various Sizes: Popular lengths from 3/16" to 7/8". Each screw type includes 20pcs, and each nut size includes 50pcs. Premium Material: Made from 304 stainless steel for excellent corrosion resistance, durability, and a clean finish. (May be mildly magnetic.) Precision Design: Fully threaded screws with sharp, accurate threads for secure fastening. Button head style offers wide bearing surface and smooth, finished appearance. Organized Storage Case: Comes in a compact, transparent, compartmentalized plastic box for easy storage and quick access. Wide Application: Suitable for electronics, small machinery, model building, furniture, repairs, and general DIY projects. ? Product Description (optimized for SEO) This 390-piece UNC Stainless Steel Assortment Kit provides the most commonly used #2-56, #4-40, and #6-32 button-head socket cap screws with matching hex nuts. Perfect for professionals, hobbyists, and DIY users, this kit covers a wide range of fastening needs. Made from high-quality 304 stainless steel, these screws and nuts deliver excellent rust and corrosion resistance while maintaining strength and reliability. The button head design offers a low profile, wide bearing surface, and a clean, finished look. All screws are fully threaded (unless noted), ensuring secure fastening and easy installation. Each size is individually packaged in a durable, clear plastic organizer case, making it simple to find the right fastener when you need it. Package Contents (390pcs total): #2-56: 4 screw sizes (3/16", 5/16", 1/2", 5/8") ? 20pcs each + 50 nuts #4-40: 4 screw sizes (1/4", 3/8", 1/2", 5/8") ? 20pcs each + 50 nuts #6-32: 4 screw sizes (5/16", 1/2", 3/4", 7/8") ? 20pcs each + 50 nuts Not recommended for high-strength fastening applications. Organized, durable, and versatile, this set ensures you?ll always have the right screw and nut at hand for your next project.