Definition
The distance from the center of a rivet or bolt hole to the nearest edge of the sheet, plate, or structural member it passes through. Standard practice in aircraft sheet metal work calls for an edge distance of at least 2 to 2.5 times the diameter of the rivet shank, measured from hole center to material edge.
Plain English
How far a rivet or bolt hole sits from the edge of the metal it goes through. Too close to the edge and the metal can tear or split; far enough in and the joint stays strong.
Context Anchor
Used in aircraft maintenance and structural repair when laying out rivet, bolt, or screw holes in sheet metal or other structural parts.
Why Pilots Care
Edge distance is a basic airworthiness check on any riveted repair. A rivet placed too close to the edge of a skin or rib will not develop full strength and can pull through the material under load, which is why inspectors and AMTs measure it carefully on every patch and splice.
Analogy
It is like punching a hole in a sheet of paper: if the hole is too close to the edge, the paper tears much more easily.
Intuition Check
Edge distance does not mean the length of the edge itself. It means the distance from the center of the hole or fastener to the closest edge of the material.
Example Sentence 1
The mechanic rejected the repair because two of the rivets had less than the minimum edge distance.
Example Sentence 2
If the edge distance is too small the skin can crack around the fastener under flight loads.