If you work with leather, chances are you've looked at various websites selling a little known, but extremely useful component called a Chicago Screw. Originally created decades ago to bind large stacks of office paper together, the Chicago screws' usefulness spans far beyond the office and has found a solid home in the leather industry, as well as construction and other markets.

What is a Chicago Screw?

A Chicago Screw is a two-part component consisting of a screw and a post used to bind materials together, similar to a double-capped rivet, except that the connection is not permanently set and can be unscrewed and reused. Typically made from brass, steel, or aluminum. 

What I like most about Chicago screws is that they're stronger than rivets and can handle much more stress. Also, since they unscrew, people can easily disassemble the things to which they're attached. For example, some of the watch cuffs that I offer utilize Chicago screws. This makes it possible for the customer to change his/her watch face without needing any special tools, other than a household screwdriver. You can even find Chicago screws on some of my leather belts. Rather than sewing or using rivets, the Chicago screw provides a durable connection and allows the customer to change the buckle at will on their new leather belt.

The available options for Chicago screws are quite varied, as seen in the above photo. All these options also bring a world of industry jargon to describe them: Slotted drivers, double-slotted, blind posts, open posts, etc. I've spoken to people in the manufacturing industry and one individual describes blind posts as "a machinists' nightmare" due to the difficult nature involved in making them. Taking a closer look in the below photo, open or blind are the main two distinctions for a post. In this example, both also have a slotted driver.

Size matters.

At the end of the day, the biggest mistake crafters, DIYers, and even some legitimate businesses make is to use screws that are too large for their needs, or more specifically, posts that are too long. With leather, you want the Chicago screw to clamp down onto/into the hide, you don't want it loose and moving freely. The screws I use on my watch cuffs are among the smallest in the world and work well for extremely thin and lightweight material. Generally speaking, the smaller the screw, the more difficult it is to source them. I've had to hire machinists to make what I need because it doesn't readily exist.

Final takeaway:

Chicago screws are used in place of rivets or sewing for a non-permanent connection.

Can be made of various materials, but brass is the preferred material when working with leather.

The smaller they are, the harder they are to find readily available for purchase.

Chicago screws can be set permanently by dropping a small amount of adhesive into the post just prior to setting.(dry fit first)