5 different sizes for your interest: Binding screws are 5 lengths: 6mm, 10mm, 12mm,15mm and 18mm, all chicago binding screws are 5mm in diameter which fits the most items High Quality: The chicago screws are made of quality carbon steel, plated with silver nickel, sturdy and rustproof, easy to bond, install and remove, these chicago nuts can be used to repeatedly with good sealing Wide Application: The screw rivets are especially suitable for leather craft decoration, bookbinding, document, book, album, DIY crafts, etc Easy to install: Just use a drill to make a 5mm diameter hole, and install the 2 pieces on each side Convenient storage: We offer beautiful plastic storage boxes. So you don't have to worry about losing some rivet screws, so you can use them again 80 pcs 5 sizes metal binding screws are made of carbon steel, which is strong and durable, with nickel-plated surface. Kit 5 Sizes head screws is ideal for leather crafts, decorating, decorating a document, book, photo album, binding, scrapbooking and other DIY crafts. Features: 1.Made of quality carbon steel material, nickel silver plated, sturdy and anti-rust. 2.Reusable: Easy to remove, install and remove; can use repeatedly. 3.Binding screws: 5 assorted sizes, 20 pieces for each size, 100 sets binding screws in total. 4.Ideal for home decoration leather crafts, bookbinding, document, book, photo album, Scrap booking, DIY, etc. 5.Organized by size in a transparent storage case for quick access and protection. Specification Product Name:Chicago screw Material:Chicago carbon steel Color:Silver Dimension : 56mm / 510mm / 512mm / 515mm /518mm Weight: 240g Quantity: 80 Packing includes: 16 sets of chicago screws (5 x 6 mm) 16 sets of chicago screws (5 x 10 mm) 16 sets of chicago screws (5 x 12 mm) 16 sets of chicago screws (5 x 15 mm) 16 sets of chicago screws (5 x 18 mm) 1 x Transparent Storage Box If you have any questions, please feel free to contact us, and we will do our best to offer you the best shopping experience.getveryrich