screw type: slot; shape: flat round head; base diameter: 8mm/0.31 inches; screw size: (4mm/0.16 inches); column rod length: 15mm/0.59 inches; total height: 19mm /0.75 inches; packaging: 30 sets of Chicago screw rivets.Chicago flat screws are made of high-hardness brass, which is not rust, wear resistance, and corrosion resistance. The is smooth and bright, no scratches and dust, waterproof. This screw column to firmly fix leather parts together to provide reliable and solid connections. The thread pillar and screw head design are closely fitted to prevent loosening or accidental separation. We Bonato Chicago Screw Leather Rivet design is simple, easy to install and disassemble. They have a threaded pillar and screw head, which can be tightened or loosen with the smallest strength, so as to easily assemble and remove leather products.We button rivet is suitable for leather craft projects, such as belts, handbags, wallets, belts, and files, books, clipboards and album decorations. These multi -functional rivets provide fashionable and practical solutions for connecting leather parts or other components. Colour:As Shown Material:brass Size:15 x 8mm Package Contents: 30 x screw rivets