These screw rivets for leather are versatile and can be used for a variety of DIY leather crafts as either fixed or decorative items. They are suitable for belts, bag and clothing decorations, key bag nails, leather shoes, stationery ledger nails, photo album nails, calendar screws, binding documents, and booking, among others.SpecificationMaterial: Carbon Steel320 Sets of 13 Sizes: Including 20 sets each of M5*4mm, M5*5mm, M5*6mm, M5*7mm, 15 sets M5*8mm, M5*9mm, M5*10mm, M5*12mm, 10 sets M5*15mm, M5*18mm, 30 sets 4*5mm, 40 sets 4*3mm and 90 sets 4*4mm. Comes with 3 sizes(M3*3mm, M4*3mm, M4*5mm)of phillips screw.Packing List: 1 Storage box, 320 sets of Chicago Screws,1 Hole Puncher, 1 ScrewdriverAdvantageThese Chicago screws are made of carbon steel and offer high hardness, anti-rust, excellent corrosion resistance, and resistant to deformation and fading, easy to disassemble and install, and they can be used for a long time in various applications. The leather screws are arranged according to size in the storage box, so you can easily store and find the size you need, and combine them freely. Various lengths are available to meet your different needs.Instruction1 Cut holes in the leather;2 Choose the right length of leather craft rivets;3 Pass the stud through the hole;4 Align the nut with the thread and tighten the screw.Note: Before placing the order, please confirm the size.