Which of the following is NOT a type of self-plugging mechanical lock rivet?

The correct answer is that RivetMate is not a type of self-plugging mechanical lock rivet. Self-plugging mechanical lock rivets, like CherryMAX and CherryLOCK, are specifically designed to form a secure connection through mechanical means and are widely used in aircraft structures for their advantages in strength and reliability.

CherryMAX and CherryLOCK are specifically engineered to allow for a one-piece installation that results in a strong bond once set. They achieve this by using a unique mechanism that locks the rivet in place as it is expanded, creating a tight fit against the materials being joined.

On the other hand, RivetMate does not fall into the category of self-plugging mechanical lock rivets. While it may be used in applications involving rivets, it does not share the same mechanism or purpose associated with self-plugging designs. Understanding the specific characteristics and intended uses of different types of rivets is crucial in aircraft maintenance and repair work.