Widely used in DIY leather craft and bookbinding: These leather screws are perfect for adding ornaments to the DIY handicraft decoration.Especially suitable for various leather crafts such as belts, handbags, leather shoes, binding documents, books, photo albums, DIY crafts. You can use it as you like. Reusable storage boxes: All the binding screws packed in a delicate and transparent box. The book screws are arranged according to size, you can easily store and find the size you need. The finish on these screws are very nice for being ran off as high production items. the finish is excellent, the screw heads are nicely chamfered (tapered off), the slots are low profile and have a professional apearence. Durable and easy to bind:The finish on these Chicago buttons are very nice for being ran off as high production items. The finish is excellent, the screw heads are nicely chamfered (tapered off), the slots are low profile and have a professional apearence, can be easy to remove and install. You can add or subtract as much paper as you like. 90 sets of 6 sizes:The chicago rivets set kit include 6 sizes,The chicago rivets set kit include 6 sizes(M5*4mm,M5*5mm,M5*6mm,M5*8mm,M5*10mm,M5*12mm). 15 sets for each size, the diameter of these screw rivtes are all 5mm(3/16 inch). 6 kind of post length are 4mm(1/6 inch),5mm(3/16 inch),6mm(1/4 inch),8mm(5/16 inch),10mm(3/8 inch),12mm(1/2 inch).Various lengths are available to meet your different needs.Date First Available: January 7, 2021. Country of Origin: China. Manufacturer: Alloypro. Item Weight: 7.5 ounces. Best Sellers Rank: #39,212 in Arts, Crafts & Sewing. Customer Reviews: 4.6 4.6 out of 5 stars 514 ratings 4.6 out of 5 stars. : B08S6TZNVL. Package Dimensions: 5 x 2.6 x 0.87 inches. Size: 4,5,6,8,10,12. Fastener Size: M5. Fastener Type: Machine Screw. Thread Coverage: Fully Threaded. Head Type: Binding. Color: Silver. Metal Type: Carbon Steel. Exterior Finish: Silver. Head Style: Binding. Drive System: Cross. Material: Silver, Carbon Steel, Leather, Nickel.