Chicago screws (also known as binding screws or sex bolts) consist of two parts: a male screw (with external threads) and a female barrel or cap (with internal threads). When assembled, they securely fasten multiple layers of material together. The male screw typically has a flat or countersunk head, while the female head can be domed, flat, or slotted (Phillips/flat/Torx®). They provide a clean appearance, allow repeated disassembly and reassembly, and do not damage the surface of the clamped material. Common applications include leather goods, paper binding, signs, luggage, and electronic device housings.
Customizable options:

Materials: Carbon steel (e.g., C1008), stainless steel (SS304/SS316), brass, copper, aluminum alloy, zinc alloy, etc.

Surface finishes: Electroplated zinc (blue/white, yellow, black), nickel plating, chrome plating, bronze plating, antique finishes (antique bronze/blackened), brushed or polished, anodized (aluminum), painting, etc.

Head styles: Domed, flat, countersunk, slotted (flathead), Phillips, Torx®, hex socket, or smooth un-slotted (decorative)

Other variables: Nominal diameter (#2–#10, M3–M10), overall length (grip range 3mm–25mm), male thread length, female barrel depth and outer diameter can be manufactured to customer drawings.
Widely used in leather booklet binding, belts, handbags, safety manuals, display signs, notebook binders, and electronics assembly.