Before driving a rivet, how should the rivet die be positioned relative to the surface of the assembly?

The correct positioning for the rivet die relative to the surface of the assembly is perpendicular. This alignment is crucial because it ensures that the force applied during the riveting process is uniformly distributed across the rivet head and the surrounding material. A perpendicular orientation allows for even deformation of the rivet shank, leading to a secure mechanical connection that maximizes joint strength and integrity.

Positioning the die at this angle helps prevent issues such as misalignment, improper seating, or uneven pressure distribution, which could compromise the quality of the rivet connection. If the die were tilted at a diagonal or horizontal angle, it could result in uneven riveting that may lead to bond failure or a weak joint. Therefore, achieving a perpendicular alignment is essential for effective riveting and contributes to the overall safety and performance of the aerospace assembly.