Definition
In sheet metal and rivet work, gauge is a measurement of the thickness of metal sheet or the diameter of wire and rivet stock. Lower gauge numbers indicate thicker material; higher gauge numbers indicate thinner material. When applied to rivets, gauge typically refers to the diameter of the rivet shank, which must be matched correctly to the thickness of the materials being joined.
Plain English
A number that tells you how thick or thin a piece of metal is, or how thick a rivet is. Smaller numbers mean thicker material.
Context Anchor
Seen in aircraft sheet-metal repair instructions, rivet layout drawings, and structural repair work.
Derivation
From Old French 'gauge,' meaning a standard measure or to measure precisely. The word has long been used in metalworking trades to mean a fixed standard for thickness or size.
Why Pilots Care
Using the wrong gauge of rivet or working with the wrong gauge of sheet metal can produce a weak joint or an improper repair, which can fail under flight loads. Repair specifications call out specific gauges for a reason.
Intuition Check
Gauge does not mean a cockpit instrument here. It means the spacing between parallel rows of rivets.
Example Sentence 1
The repair called for rivets of a specific gauge to match the thickness of the skin panel being replaced.
Example Sentence 2
Always verify the rivet gauge before installation to ensure the hole diameter is correct.