Layout And Form A U-Channel Flashcards
For maximum strength of a formed sheet metal fitting, should the bend be made along or across the grain?
Across
What determines the minimum bend radius that can be used when forming a sheet metal structural fitting?
The alloy, the metal thickness, and its hardness
What is meant by the neutral axis in a sheet of metal?
A plane within the metal that neither stretches nor shrinks when the metal is being bent
What is a mold line in the development of a flat pattern for a formed metal part?
An extension of the flat sides beyond the radius
What is a bend tangent line?
A line in a flat pattern layout at which the bend starts
What is meant by setback?
The distance the jaws of a break must be set back from the mold line to form a bend
What is meant by bend allowance?
The actual amount of metal in a bend. It is the distance between the bend tangent lines in a flat pattern layout
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 tangent line.
What type of device is a Cleco fastener?
A patented fastener that is inserted in the rivet holes and used to hold two pieces of a sheet metal together until they can be riveted
What is the main function of throat less shears in an aircraft sheet metal shop?
Throat less shears are used to cut mild carbon steel up to 10-gage, and stainless steel up to 12-gage. 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 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 jiggle in a piece of sheet metal?
A joggle is a small offset near the edge of a piece of sheet metal that allows the sheet to overlap another piece of metal
