Rivet Joint Failure — Root Cause & 8D Corrective Act...

Symptoms Rivet head pulls through (or into) the workpiece material Loose rivet / relative play between joined parts after installation Cracking or deformation around the rivet hole Joint fails shear or tensile pull test below specification Affected Components Self-pierce (SPR), solid and blind rivets in sheet-metal assemblies Aluminum / steel stack-ups in automotive body, chassis, battery trays Multi-layer joints with material thickness variation Structural and semi-structural joints Detection Methods Visual + gauge: head flushness, hole deformation, cracking Mechanical test: shear and tensile pull; record peak load and failure mode (head pull-through vs. rivet fracture) Cross-section / macro etch: check rivet flaring, fit-up gap, hole fill In-process: squeeze-force trace; rivet length / diameter verification Possible Causes Hole alignment offset between layers (stacked misalignment) Rivet length insufficient for total material stack thickness Squeeze force too high → material cracking around hole; too low → poor flare Material thickness stack variation exceeding rivet tolerance range Worn punch / die bushing → oversize hole Wrong rivet for the material combination 5-Why Example Problem: Rivet head pulled through the top layer of a bonded + riveted body panel Why head pulled through? → Top-layer hole 0.5 mm oversize Why oversize? → Punch bushing worn, punch...