Hva betyr blindnaglehopper?

Blind naglehoppehode: fordi naglen ikke pakker spikerhodet, vil det føre til at naglehoppehodet.

https://www.yukerivet.com/news/the-core-of-the-blind-rivet-is-not-completely-pulled-out-what-is-the-reason-for-the-fracture/