a nickel copper alloy used in the aerospace industry to make AC parts that withstand high temperatures and corrosion. Commonly found in aircraft frames, rivets, exhaust systems, and safety wiring.

revolves around the process of stretching or shrinking metal. Structure means to lengthen or increase a particular area of metal while shrinking means to reduce an area. Several methods of stretching and shrinking may be used, depending on size, shape, and contour of part being formed

sheet of metal typically made from aluminum alloy used in construction acting as outer skin of the plane

cutting a large sheet of stock into smaller pieces suitable for the next operations in stamping, such as drawing or forming

specific thickness of a flat sheet of metal

the smallest radius the inside of a bend may be

the radius of the inside of a bend in a piece of sheet metal, tubing, or wire bundle

the neutral axis of a piece of material being bent is a place within the material along which there is no stress. The neutral axis is located approximately halfway (actually 44.5% of the thickness of the material from inside the bend) The material on the outside of the bend is under a tensile stress and that on the inside is covered under a compressive stress. Therefore the non stress area is along the neutral axis

used for cleaning, corrosion control, and fuel tank maintenance. caustic solutions clean engine parts by removing carbon deposits and oily substances

a line used in the developement of a flat pattern for a formed piece of sheet metal. The mold line is an extension of the flat side of a part beyond the radius. The mold line dimension of a part is the dimension made to the intersection of mold lines and is the dimension the part would have if its corners had no radius

a measurement used in sheet metal layout. Setback is the distance the jaws of a brake must be setback from the mold line to form a bend. Setback for a 90 degree bend is equal to the inside radius of the bend, plus the thickness of metal being bent. For a bend of other than 90 degrees, a power called K factor must be used.

the longer part of a formed angle

a process that involves heating and coling metal components to improve their mechanical properties. It is used to make aircraft parts stronger, more ductile, and more reistant to impact. Types of heat treatment include annealing, quenching, and tempering

a metal working technique used in AC mainteance to strengthen metal without heat. It is also known as "work hardening".

a solid, cast piece of metal, typically made from aluminun, or titanium alloys, used as a raw material to manufacture aircraft components like fuselage parts, wings and landing gear. In short, ingots are used because they provide a convient way to store and transport large quantities of high quality metal for aircraft construction.

K Factor is a constant used to calibrate fuel flow meters in aircraft. It represents the number of pulses needed to measure a specific volume of fuel.

a straight line that marks the beginning of a bend in a sheet metal or tube. It is the point where the bend allowance and setback are measured from

bend allowance is the extra length of material added to the flat piece of sheet metal to account for stretching during bending. It is used to calculate the final length of a bent part and is important for ensuring precise dimensions in aircraft manufacturing.

a line drawn on a sheet metal layout that is one bend radius from the bend tangent line. The sight line is lined up directly below the nose of the radius bar in a cornice brake. When the metal is clamped in position, the bend tangent line is the correct position for the start of the bend.

a relief hole is a small hole drilled into sheet metal to prevent cracking and distribute stress. Relief holes are often drilled at the intersection of two bend lines. Relief holes allow material to absorb stress chnages more gradually.

a curve formed in kmkore than one plane. The surface of a sphere is a compound curve.

a piece used to stregthen a mounting location or repair a damaged area. Doublers can be used for a variety of aircraft.

a surface that is curved outward with its outer edges lower than the center

a metal shape used in AC to make parts. Its made by heating aluminum alloy and forcing it thru a die to create a desired shape. Extruded aluminum angles are stronger than non extruded angles

a surface that is curved outward with its outer edges lower than the center

holes cut in AC parts to reduce weight and increase durability.

a hand operated mechanical tool used to apply precise, controlled force for tasks like installing or removing bearings, bushings, rivets, or other components that require a press fit.

a bend in sheet metal that allows one sheet to overlap another while keeping the surface smooth. Used to create joints and splices in aircraft

a sheet metal forming press where a piece of sheet metal is simealtaneously stretched and bent over a die to make complex curved shapes

a type of lightening hole that consists of two mathcing parts, female and male

block used to bend metal, or building blocks used to calculate changes

a table or graphical representation that provides values for "bend allowance" which is the extra length of material needed to account for the stretching that occurs when bending sheet metal

Total developed width - the width of material measured around the bends from edge to edge

changing the shape or contour of a flat service by either stretching or shrinking the material in a certain area to produce curves, flanges, and various irregular shapes

They differ significantly due to volume and precision requirements Tooling differences include specialty fixed tools such as jigs and precision modes used for stamping

It is required when the metal has become work hardened or when it goes thru excessive bending. Annealing restores the metals malleability.

against the grain at a 90 degree angle

compare the bend to a known radius template or use a flexible rivet. Trace the curve and check to consistency against a described radius

the intersection of two mold lines at a part. Mold lines dimensions are made between mold points

it undergoes a transformation that is critical to understand how the material behaves and is also a line that experiences no stretch or compression

BTL marks the boundary between a flat portion of the metal and the start of the bend radius. The bend alowance is the curved section. They all make up the flat.

K value is the tangent of one half the bend angle

SB = Raduis + Thickness of the metal

a closed angle is less than 90- degrees when measured or less than 90 degrees when the amount of bend is measured. An open angle is more than 90 degrees when measured between legs, or more than 90 when the amount of bend is measured

if the radius bend is too small, stresses and strains weaken the metal and may result in cracking

The K Factor Charts shows the K factor for a 94 degree bend is 1.072

The TDW is less than the mold line dimensions since the metal is bent on a radius and not to a square corner a mold lines dimensions indicate

KFACTOR(Radius+Thickness)

Setback can be calculated with a formula or can be found in a setback chart available in aircraft mainteance manuals (SMRs)

Step One: Determine the correct bend radius Step Two: find the SB Step Three: Find the length of the flat line dimensions Step 4: find the bend allowance STep 5: find the total developed width of the material step 6: Flat pattern layout Step 7: Draw the sight on the sight patterns

MLD-SB

Two setbacks need to be subtracted from the center flat

degree of bend, radius of the bend, thickness of metal, and type of metal used

TDW = Flats + (Bend allowance x # of bends)

to the radius of the bend (R) add 1/2 thickness of the metal (1/2T) or the radius of the circle of the neutral axis. Compute the circumference by mutiplying the radius of the neutral line by 2pi

2Pi(R+1/2T)

left side of the table can find thickness, then look right to locate bend radius, then note the bottom number in the block, then multiply by bend angle.

It assumes all bends are the same. It may be incorrect if springback or Kfactor are not accounted for.

Errors in calculating the bend allowance, miscalculating the setback or material is stretched wrong

1) add shim or backing material 2) bend incrementally 3) use forming block or hand forming