blind 6.5x12.5. Rivet. A fastener which consists of a shaft and a head on one end, and when the shaft end is installed it expands and holds the B Pillar in place. A fastener which consists of a shaft and a head on one end, and when the shaft end is installed it expands and holds the B Pillar Reinforcement in place. A Rivet used to attach the Frame Side Member to it's mounting point. A Rivet which secures the fender apron to it's mounting point. Body B - Reinforcement. Fender Apron. Frame Side Member. Inner. Pop. Rail end. Included with: Rear Inner structure.