Definition 1 of 2
Definition
A sheet metal layout term referring to a bend angle greater than 90 degrees, where the two flanges form an obtuse angle and open outward away from each other.
Plain English
A bend in sheet metal that is wider than a square corner — the two sides spread apart instead of meeting at a right angle.
Context Anchor
Seen in aircraft sheet-metal repair, bend layout, bracket fabrication, and airframe structural drawings.
Derivation
‘Open’ here means ‘spread apart’ rather than ‘closed up tight.’ A 90-degree corner is considered the closed reference; anything wider than that is described as opening up.
Why Pilots Care
For maintenance work, the correct open angle helps a repair part fit properly and carry loads the way the design expects.
Intuition Check
Open does not mean a hole or an uncovered space here. It means the angle is wider than 90 degrees.
Example Sentence 1
The technician laid out the bracket with an open angle of 110 degrees to match the contour of the fuselage skin.
Example Sentence 2
An open angle was formed on the brake to match the contour of the fuselage frame.