When establishing or replacing parts for piping, tubing, and other similar systems that feature many interconnected components, it can oftentimes be difficult to find exact fits for connecting installations. For fluid applications in particular, or for those where fluids must not enter a system, having imperfect fits can lead to leaking, damage, and more. As such, parts often require a middle component to act as a compressed seal to close off the assembly. An O-ring, or packing, is a torus-shaped mechanical gasket that is used in such instances, providing countless assemblies with sealing action through its simplistic design. As O-rings are widely used across many applications as one of the most common sealing components, understanding their construction and functionality can be highly beneficial.