There are many kinds of fasteners, one of which is the rivet which can be used for a variety of different applications. The process of riveting dates back to the days before welding and the use of bolts were common in construction. Many old bridges scattered across the world are still functioning with their original rivets. There are many kinds of rivet-type fasteners each of which is employed for a certain purpose; however it is pop rivets that we are most interested in here.
Before we take a look at pop rivets though we think it is necessary to explain the concept of how rivet-type fasteners work. A rivet is a small metal shaft with a head on one end that is inserted through two adjacent sheets of material, often metal, to hold them together. The clasping effect of this kind of fastener occurs when the end without the pre-made head is bent or ‘bucked’ which is why this end of the rivet is generally called the ‘buck-tail’ end. The fastener expands as it is riveted in addition the buck-tail effect of the bent end which lends extra grip. Unlike screws, rivets do not have a spiral thread and generally two riveted surfaces are quite narrow in breadth so a screw would not work here as screws normally hold by penetrating deeply into thick materials and grip that way.
The phrase ‘pop rivet’ has a peculiar ring to it that sounds like the noise a riveting gun makes. Incidentally, you will need a special riveting gun in order to successfully squash the buck-tail of any kind of rivet so that it holds the two construction surfaces in place and this goes for all rivet-types, not just pop rivets. This last mentioned variety of rivet is also often referred to as a blind rivet and is not as capable of bearing heavy loads as other kinds of rivets. It is ‘blind’ because the riveting is done from the one side whilst the other remains unseen.
Pop rivets have something called a ‘mandrel’ in the middle which is the portion that expands when it is fastened and then snaps off at the end. One of the problems with these rivet-types is that the mandrel is susceptible to loosening as a result of vibrations. If the mandrel falls out, the rivet will be hollow inside and therefore not very strong and because of the mandrel this rivet-type tends to rust more easily.
The interesting thing about pop rivets, however, is that before they were invented it wasn’t possible to rivet from only one side of a construction and herein lies its value as a fastener. When it is impossible to gain access to the back end of a structure is when this rivet-type comes in handy. A joint is a good example of where a blind rivet-type might be used. Another advantage is that it is possible to work in situ with this type. They are also easy to use and have a neat appearance.