Definition
A sheet metal forming process in which a small cone-shaped depression is pressed into thin aluminum sheet around a rivet hole so that a flush (countersunk) rivet head can sit level with the surface of the skin. Dimpling is used instead of machine countersinking when the metal is too thin to be safely countersunk without removing too much material.
Plain English
Pressing a small funnel-shaped dent around a rivet hole in thin metal so a flat-topped rivet sits flush with the surface instead of sticking up.
Context Anchor
Seen in aircraft maintenance and sheet-metal repair, especially when working with flush rivets on thin aluminum skin.
Derivation
From the everyday word 'dimple' — a small natural dent in a surface, like the dimple in a cheek. The sheet metal process gets its name because it presses that same shape into the metal.
Why Pilots Care
Flush rivets created by proper dimpling maintain smooth airflow over the skin and reduce drag.
Grounding Statement
Picture the metal around a rivet hole being pressed downward just enough to make a neat little seat for the rivet head.
Intuition Check
Dimpling is not just any dent in the aircraft skin. Here it means an intentional, shaped depression made for a flush rivet.
Example Sentence 1
The mechanic finished dimpling the skin panel before setting the flush rivets along the wing's leading edge.
Example Sentence 2
Improper dimpling can leave the rivet heads slightly proud and disturb the airflow over the wing.