Description: Threaded post lets you open and reattach pieces when needed. widely used in binding photo album, leather craft, paper craft etc. Material: Brass Cap Diameter（ Flat）：8mm，10mm Cap thickness: 2mm Post Length: 4mm, 5mm, 6mm, 7mm, 8mm, 10mm, 12mm, 15mm, 20mm. Size： 8x9mm 10x9mm 10x4mm 10x5mm 10x6mm 10x7mm 10x8mm 9.5x6mm 10x10mm 10x12mm 10x15mm 10x20mm 8x3mm 8x15mm 8x4mm 8x5mm 8x6mm 8x7mm 8x8mm 8x10mm 8x12mm The height of the middle section (post）, not including the flat heads is 4mm-20mm. When the post length is ＞ 5mm,the length of the screw thread is 6mm. When the post length is ≤5mm,the length of the screw thread is 4mm. Package include: 20pcs+ a punching tool High-Quality Material: These stud screws and Chicago screws are made of solid brass, ensuring durability and longevity. Versatile: Ideal for leathercraft, these screws and rivets can be used for belts, bags, jackets, shoes, and other leather items. Easy to Use: The screw and rivet design makes them easy to install and replace, without the need for any special tools. Stylish: The brass finish adds a touch of elegance and sophistication to your leather projects, making them stand out from the rest. Secure: The screw and rivet design ensures a secure hold, preventing items from coming loose or falling apart.