Metal Chicago Screws Assorted Kit Book Binding Posts Leather Rivets BoltsDescription:Material: Chicago screws are made of high quality metal, rustproof and durable.Size: Stud head diameter (M5) 5mm, stud length 5mm, 10mm, 15mm, 25mm, 35mm, 45mm (6 sizes); Screw head diameter (M4) 4mm, thread length 4mm, 5mm.Quantity: 140 Pieces (70 Sets), including 5mm (20Set), 10mm (20Set), 15mm (10Set), 25mm (10Set), 35mm (5Set), 45mm (5Set).Color: SilverUses:Book binding screws are widely used for binding and organizing loose-leaf paper, books, DIY handbooks, documents, etc. They can also be used as handmade leather screws for leather crafts such as belts, bags and shoes.Warm Tips:The product is a small part, please pay attention to children to avoid accidental ingestion when using.