Metallic Structures Flashcards
What is a sight line?
A line drawn on a flat pattern layout within the bend allowance that is one bend radius from the bend tangent line. When the sight line is directly below the nose of the radius bar on the brake, the bend will start at the bend tangent line.
What is the main function of throatless shears in an aircraft sheet metal shop?
Throatless shears are used to cut mild carbon steel up to 10-gauge, and stainless steel up to 12-gauge. They can be used to cut irregular curves in the metal.
What kind of metal forming is done by a slip roll former?
Simple curves with a large radius.
What kind of metal forming is done by bumping?
Compound curves in sheet metal.
When forming a curved angle, what must be done to the flanges?
The flanges must be stretched for a convex curve and shrunk for a concave curve.
When hand-forming a piece of sheet metal that has a concave curve, should the forming be started in the center of the curve, or at its edges?
Start at the edges and work toward the center.
What is meant by a joggle in a piece of sheet metal?
A joggle is a small offset near the edge of a piece of sheet metal that al- lows the sheet to overlap another piece of metal.
