【90 sets of 6 sizes】Chicago rivet stud set includes 6 sizes (M5*4mm, M5*5mm, M5*6mm, M5*8mm, M5*10mm, M5*12mm), 15 PCS of each size. 【High quality material】 these Chicago screws are made of high quality carbon steel with nickel plated surface, clear grain, smooth and burr-free, waterproof and durable, no rusting. 【Excellent design】 chamfered design is safer, deep thread, not easy to slip during rotation, even force and good tightening strength. 【Widely used】 These leathercraft rivets are especially suitable for DIY various leather crafts, as a fixed or decorative items used. For example: belt connection, bag decoration, clothing decoration, key bag nails, stationery ledger nails, photo album nails, calendar screws, etc. 【Easy to install】 pick the right length of screw, put the stud through the hole, align the nut with the stud and tighten the screw. Note: When installing, the hole please do not exceed 4mm, if the hole is too large, it is easy to cause the screw to fall off. ality material】 these Chicago screws are made of high quality carbon steel with nickel plated surface, clear grain, smooth and burr-free, waterproof and durable, no rusting. 【Excellent design】 chamfered design is safer, deep thread, not easy to slip during rotation, even force and good tightening strength. 【Widely used】 These leathercraft rivets are especially suitable for DIY various leather crafts, as a fixed or decorative items used. For example: belt connection, bag decoration, clothing decoration, key bag nails, stationery ledger nails, photo album nails, calendar screws, etc. 【Easy to install】 pick the right length of screw, put the stud through the hole, align the nut with the stud and tighten the screw. Note: When installing, the hole please do not exceed 4mm, if the hole is too large, it is easy to cause the screw to fall off.