What feature do most rivets used in aircraft construction have?

In aircraft construction, most rivets are designed with dimples. This feature is fundamental because dimples help in the proper seat and alignment of the rivet, ensuring it provides a strong and reliable fastening connection between metal sheets or parts. The dimple on the rivet head allows for controlled deformation as the rivet is installed, which optimizes the joint's strength and integrity.

The dimples also facilitate the rivet to be driven into place without slipping, ensuring that it forms a tight connection between the materials it is fastening. This is crucial in aviation, where structural integrity and reliability are paramount for safety. Using rivets with the appropriate dimple design contributes to the overall performance and durability of the aircraft's structure.

In contrast, grooves, hooks, and notches do not provide the same mechanical advantages or functionality for riveting in aircraft construction. While these features might have applications in other contexts, they are not standard characteristics of rivets used in assembling aircraft.