Bending allowance

thickness(t)

the thickness of the metal being bent

neutral axis

bending compresses the metal on the inside of the bend and stretches the metal on the outside of the bend. (half between these two extremes lies a space that neither shrinks nor stretch. THIS WHERE THE BEND ALLOWANCE IS CALCULATED.

box and pan brake

is equipped with a series of removable and adjustable steel fingers of varying widths. it is often referred to as finger brake . is able to form boxes, pans, and other similarly shaped objects

bend radius

is the radius of the bend. it is always measured from the inside of a bend, unless stated otherwise.

k number

one of 179 numbers on k chart that correspond to one of the angles between 0 -180. use when bends are not 90 degrees

bend tangent line

the line at which the metal starts to bend and the line at which the metal stops curving

lighting holes

are cut into the rib section; fuselage frames and other structural parts to reduce the overall weight of the aircraft to keep the member from weakening, flanges are often passed around the holes to strengthen the area.

relief holes

are drilled at intersections when two bends intersect to make room for the metal contained in the flange. they prevent strains from being set up at the intersections

adjustments for bar brake

are to compensate for: thickness of material width of fold sharpness of fold angle of fold

bar folder

designed for use in forming bends or folds along the sheet metal, the bar folder is primarily used in forming of : SMALL HEMS FLANGES SEAMS EDGES

uses of cornice brake

extremely useful when forming bends or shapes such as: single hems, double hems, lock seams, various other shapes.

cornice brake

is designed to bend large sheets of metal. The cornice brake are available in a range of sizes from 3'-12' long adjustable to handle a variety of metal thickness.

flat

is equal to the base measurement minus the setback

factors of bend allowance

radius of bend type of metal degree of bend thickness of the metal

base measurement

shows each outside dimension and the overall dimension of a formed part

bend line

siight line metal thats being formed is set even with the nose of the brake.

bend allowance

the amount of material consumed in making a bend

BEND ALLOWANCE FACTORS

the degree of the bend will affect the overall length of the metal, where as the thickness influences the radius of bend.

setback

the distance from the bend tangent line to the mold point.

mold point

the intersection of extension lines outside of the formed part

mold line(ML)

the line formed by extending the outside surfaces of the leg and flange

leg

the longer part of the formed angle

flange

the shorter part of the a form angle

sight line

the slight line or brake line is mark on a flat sheet that is set even with the nose of the radius bar of the brake. (serves as a guide)