All About Blind Rivets
Fasteners are components that are paramount to countless assemblies, securing parts together while also distributing loads and forces. Fasteners can come in various forms, including those such as rivets, screws, nuts, and washers. Blind rivets in particular are a specialized rivet, and they are often used for applications such as aircraft construction. Unlike a conventional rivet, blind rivets can be installed from one side of an assembly, making them very beneficial for a number of uses.
For standard rivets, their construction will result in a fastener that has a head on one side and a smooth, cylindrical shaft across the other. To secure an assembly, the tail-end of the rivet is passed through a preformed hole of a component. With the use of a mallet or specialized tool, the tail is then deformed as to create a second head on the opposite side of the assembly. While a standard rivet creates a very strong and permanent fastening solution, the installation method requires access to two sides as the component needs to be inserted from one and upset on the other.
With a blind rivet, on the other hand, the specialized design of the fastener solves the issue of requiring two sides of access. With the blind rivet, a nail-like mandrel passes through the body of the fastener and the neck is weakened. To install such rivets, the component is passed through a preformed hole, and the mandrel is placed into a special installation tool. By pulling on the mandrel, forces will begin to deform the weakened area and a new head will be created. This results in an assembly similar to conventional fasteners, all while only requiring one side for installation.
Depending on one’s needs, blind rivets can come in a number of styles to accommodate varying applications. The most common head styles for blind rivets are dome, large flange, and countersunk designs. It is also important to note that blind rivets may be produced with a number of materials to achieve specific strength or corrosion resistance qualities. Generally speaking, the common blind rivet variations are aluminum rivets with aluminum mandrels, aluminum rivets with steel mandrels, steel rivets with steel mandrels, stainless steel rivets with steel mandrels, and stainless steel rivets with stainless steel mandrels.
Beyond the materials of the rivet, hole size and grip range are also important to take note of. Grip range is extremely important, as it is what will determine whether the fastener will stay secure or loosen quickly. Generally, the material thickness should never be less than the minimum grip range. Having too much thickness is also problematic as it may cause the rivet to be unable to set correctly. The size of the rivet will also affect strength, and shear and tensile strength tend to rise as the rivet grows larger.
Aside from being quick and easy to install, blind rivets are also desirable for their ability to withstand vibrations and tampering as well as shear and tensile strength loads. If more strength is required for an assembly, one may add square or round washers to increase support. Washers can also help prevent pull-out, making them useful for many applications in which a larger diameter surface is needed. Regardless of blind rivet type, it is important to ensure that the mandrel is installed correctly when implementing the component as it will ensure that the assembly is secure and reliably fastened.
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