Different Sizes to Choose From: The binding screws are available in 5 lengths: 6mm, 10mm, 12mm, 15mm and 18mm. All Chicago set screws are 5mm in diameter, making them suitable for most items. High Quality: The Chicago screws are made of high quality carbon steel, silver nickel plated, sturdy and rust resistant. They are easy to bind, install and remove. These Chicago nests are reusable and provide a good seal for photo albums, DIY crafts, etc. Easy Installation: Just use a drill to drill a hole with a diameter of 5mm, then install 2 pieces. Convenient Storage: We provide beautiful plastic storage boxes. So you don't have to worry about losing any rivet screws, so you can use them again. 80pcs of 5 metal sizes binding screws are made of carbon steel, durable and nickel plated. Set of 5 sizes of head screws. Perfect for leather, craft decorations, decorative documents, books, albums, bookbinding, scrapbooking and other DIY crafts. Features: 1. Made of high quality carbon steel material, silver, sturdy, rustproof and nickel-plated. 2. Reuse: Easy to disassemble, install and disassemble; it can be reused. 3. Links: 5 sizes, 20 pieces each, 100 sets of binding screws in total. 4. Ideal for decorating leather crafts, bookbinding, documents, books, photo albums, scrap booking, DIY, etc. 5. Arranged by size in seamless case for quick access and protection. Shipping Color: Silver Dimensions: 5 6mm/5 10mm/5 12mm/5 15mm/5 18mm Shipping Quantity: 1 Carton