Aluminum post and screws, also known as Chicago screws, are terrific parts for a wide variety of uses. Most often, they are used to bind booklets and corporate reports together. Other uses are as varied as binding together leather goods or even retail fixtures and displays.
One feature of these parts is that the screws (male parts) top out at 3/8-inch in length, while the posts (female parts) are available in longer lengths. It is the 3/8-inch screw that is coupled with all of the longer posts and this results in a somewhat confusing combination of part lengths that we’ll address in our sizing chart below.
If you’re not already confused, there’s this: For small posts, the opposite is true – longer screws are coupled with shorter posts. This is because the shortest posts feature an open-style head (shown above) and, when fully inserted, the slightly longer screws fill the open-style head. Trying to describe this with language alone is an exercise in frustration. We’re confident that the best way to communicate the minutia of these parts is through a chart, and we’ve made one for you below. Here’s all you’ll ever need to know about the sizing of Popco’s aluminum post and screws.