Chicago screws

Chicago screws, also called sex bolts or binding posts, are a two-piece fastener made of a barrel with internal threads and a matching screw that passes through stacked layers of leather and threads into the barrel from the other side. They come in various lengths and post diameters to fit different leather thicknesses.

Their main advantage over stitching or rivets is that they can be unscrewed and taken apart again, which makes them useful for adjustable straps, replaceable panels, or any piece that might need disassembly for repair or a strap swap later on. They also add a small hardware accent to the front and back faces of a piece.

Choosing the right length is important, since a post too short will not fully engage its threads through thick, layered leather, while one too long leaves an ugly gap or has to be trimmed down. Threadlocker or a drop of glue helps keep screws from working loose over time with regular use and flexing. A common mistake is picking a length based on a single layer's thickness and forgetting to account for every layer being joined.