What type of die is used in the rivet gun for installing Hi-Loks?

The correct answer is the bell die, which is specifically designed for the installation of Hi-Loks. Hi-Loks are a type of fastener used in aerospace applications, providing a combination of both bolt and rivet features. The bell die's design allows for effective and uniform application of force during the installation process. Its shape helps distribute the compressive forces evenly around the Hi-Lok shank as it is being installed, ensuring that the fastener is secured properly and maintaining the integrity of the assembly.

Using a bell die is crucial because it accommodates the unique geometry of Hi-Loks, allowing for optimal engagement with the fastener and reducing the risks associated with improper installation, such as damage to the component or the fastener itself. This die shape promotes a proper fit, which is vital in aerospace assemblies where safety and reliability are paramount. Other die types, while serving purposes in different fastening methods, would not provide the same effectiveness when dealing with Hi-Loks.