I imagine the rivet shown here looks very familiar to most mechanical engineers – at first glance, it looks like a typical metal pop rivet. Upon closer inspection though, you’ll notice the wide head and slotted body; this is an all-plastic expansion rivet designed to be used in similar manners as a pop rivet. It’s a good choice when working with softer materials or where a high clamping force is not needed. I’ve seen flat metal washers used on the back side of riveted joints to help protect the parts from the rivet’s clamping force; a rivet like this would have been a much better choice in that case. They’re made by Fastex.