Definition
The stress produced in a structural component by the pressing or squeezing action of another part against it, typically where a fastener such as a bolt, rivet, or pin pushes against the wall of the hole it passes through.
Plain English
The squeezing force one part puts on another where they press against each other — most often where a bolt or rivet pushes sideways against the edge of its hole.
Context Anchor
Seen in aircraft structures, sheet-metal repairs, riveted or bolted joints, and discussions of whether a fitting or fastener hole can safely carry a load.
Derivation
‘Bearing’ comes from the Old English ‘beran’, meaning ‘to carry or support a load.’ In structures, one surface ‘bears’ against another — it carries the load by pressing on it. That is exactly what bearing stress describes.
Why Pilots Care
Excessive bearing stress can elongate holes, weaken joints, and lead to structural failure if not detected during maintenance.
Analogy
Think of a heavy table leg pressing into a soft floor. The weight is carried at the small contact area under the leg, and too much pressure can leave a dent. Bearing stress is the structural version of that contact pressure.
Intuition Check
Bearing stress is not a compass bearing and not the stress a pilot feels. Here, bearing means carrying a load at a contact surface.
Example Sentence 1
If the rivets are too small for the load, bearing stress can elongate the holes in the skin and weaken the joint.
Example Sentence 2
Oversized washers were added to reduce bearing stress on the thin aluminum skin.