Definition
A hand-held tool used in aircraft sheet metal work to form the manufactured head of a rivet against the work, or to drive and shape the shop head when bucking is not practical. The working end is shaped to match the contour of a specific rivet head (such as a universal or brazier head) so the rivet is driven without marring it.
Plain English
A small handheld tool with a shaped tip that fits over a rivet head. You strike or hold it against the rivet so the rivet keeps its proper shape while it is being installed.
Context Anchor
Seen in aircraft sheet-metal repair and maintenance when solid rivets are installed by hand instead of with a powered rivet gun.
Derivation
Set in tool-making language means a tool shaped to form or finish a part to a fixed pattern. A hand rivet set is therefore a hand tool shaped to form a rivet to its proper finished pattern.
Why Pilots Care
Properly set rivets maintain the structural strength of the airframe; loose or damaged rivets can compromise safety in flight.
Analogy
It is like using a nail set in woodworking: instead of striking the fastener directly and damaging the surface, you strike a tool shaped for the job.
Intuition Check
A hand rivet set is not a collection of rivets. Here, “set” means a tool used to install a rivet and leave it correctly seated.
Example Sentence 1
The technician selected a hand rivet set matched to the universal head rivets being installed on the wing skin.
Example Sentence 2
After removing a loose rivet from the wing, the technician used a hand rivet set to install and set the replacement by hand.