A rivet is a cylindrical piece of steel with a forged head used to fasten two separate materials. There are many kinds of rivets and each is used differently depending on what materials are joined and how they are being joined. Rivets often join large pieces of metal, although smaller rivets can join wood and paper materials. Nowadays in heavy industry and steel fabrication, riveting has been largely replaced by welding.
Although there can be many types of rivets based on shape, material and function, the most common rivets are standard, countersunk and blind rivets. Standard or universal rivets are used when a smooth exterior is unnecessary. It is also used on surfaces that will not fit against another part. Countersunk rivets are used where smooth surfaces are necessary and where joining pieces rely on flat surfaces. In this instance, a standard rivet’s head would interfere. Lastly, blind rivets are used when a bucking bar will not fit on one side of the materials being joined.
There are different methods for joining different rivets as well. Hand riveting is done with a bucking bar or a blind rivet. However, there are also cold riveting and hot riveting. When the rivet is pushed through the hole, the bucking bar acts as a barrier that deforms the end of the rivet into a head. The head keeps the pieces together. In cold riveting, the rivets are refrigerated before use. This keeps them soft and malleable, which then cool and harden at room temperature. In hot riveting, the rivets are at room temperature but then heated before use.
Rivets have been used for hundreds of years, and before the advent of welding techniques, they were used widely to produce ships. During World War I, rivets put together the naval dreadnaughts, and during World War II, rivets were used heavily in the construction of aircraft. Rivets have also been used to hold together bridges, skyscrapers and other large construction projects.
Rivets still have several advantages over other fastening methods. First, rivets are inexpensive. They can also be easy to assemble. Rivets are strong, lightweight and durable. Also, rivets can join many kinds of materials of different thicknesses. During the finish, rivets can be flush and polished to blend in with the material or can be painted over.
The main disadvantage with rivets is their inability to be disassembled. In order to replace a rivet, the existing rivet will need to be drilled out. Another large disadvantage is that rivets are not airtight. Unless a sealant is used around the rivet, water and air can seep through.