Definition
The distance between the centers of adjacent rivets in the same row of a riveted joint, measured along the line of the row.
Plain English
How far apart rivets are spaced from one another along a single line of rivets.
Context Anchor
Seen in aircraft sheet-metal repair, inspection, and repair layout instructions.
Derivation
Pitch' here comes from an old English use of the word meaning the regular spacing between repeating items, the same sense used in 'thread pitch' on a screw or 'propeller pitch.' It tells you the distance from one item to the next in a repeating pattern.
Why Pilots Care
Correct spacing keeps the joint strong while avoiding extra holes that could weaken the skin.
Analogy
Rivet pitch is like the spacing between stitches in a seam. If the stitches are too far apart or uneven, the seam may not hold as well.
Intuition Check
Do not read pitch here as aircraft nose attitude or sound. In rivet pitch, pitch means spacing between rivets.
Example Sentence 1
The structural repair manual specified a rivet pitch of one inch along the seam.
Example Sentence 2
Inspectors checked the rivet pitch along the fuselage seam to confirm it met specifications.