Definition 1 of 2
Definition
The factory-formed, pre-existing head of a solid rivet — the rounded or shaped end already in place before the rivet is installed. It is the opposite end from the shop-formed 'bucked' tail (the driven head) created during installation.
Plain English
The end of a rivet that already has a head on it when you take it out of the box. The other end is flat and gets squashed into a second head when you install the rivet.
Context Anchor
Seen when installing or inspecting solid rivets in aircraft skin, panels, and structural parts.
Derivation
Called the 'shop head' because it was formed at the manufacturing shop (the factory) before the rivet ever reached the technician. The matching end formed during installation is the 'bucked' or 'driven' head, made on the job.
Why Pilots Care
Knowing which end is the shop head matters during installation and inspection. The shop head sits flush against one side of the structure; the driven head is formed on the other side. Mixing them up leads to incorrect rivet selection, wrong-side installation, or misreading inspection callouts.
Analogy
It is like putting a small metal peg through two sheets and then flattening the far end so the peg cannot pull back out.
Intuition Check
Do not read “shop head” as a part bought from a shop, or as the original head already on the rivet. In aircraft riveting, the shop head is the head created during installation.
Example Sentence 1
Before driving the rivet, he seated the shop head firmly against the skin so the bucking bar could form a clean tail on the opposite side.
Example Sentence 2
A correctly formed shop head should be one and a half times the diameter of the rivet shank.