Definition
The portion of a part's surface that is in physical contact with, and supports load against, another part. In aircraft hardware, the bearing surface of a bolt is the underside of the bolt head and the face of the nut or washer where they press against the structure being clamped.
Plain English
The exact area of a part that actually touches and pushes against another part to carry the load between them.
Context Anchor
Seen in aircraft maintenance descriptions for moving or loaded parts, such as wheels, hinges, control connections, and engine parts.
Derivation
Bearing comes from the Old English beran, meaning to carry or to bear weight. The bearing surface is literally the surface that bears (carries) the load between two parts.
Why Pilots Care
If a bearing surface is damaged, corroded, or improperly seated, the load doesn't transfer evenly. That can lead to loose hardware, worn parts, or structural failure. Mechanics inspect bearing surfaces carefully when assembling or torquing components.
Intuition Check
Do not read “bearing” here as a direction to a place. Here, “bearing” means carrying or supporting pressure from another part.
Example Sentence 1
Before installing the bolt, the mechanic cleaned the bearing surface to make sure the washer would seat flat against the metal.
Example Sentence 2
Lubricant was applied to the bearing surface to reduce friction in the nose-gear pivot.