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# Press brake chart

## Press brake chart

A press brake chart is a graphical representation of the relationship between the depth of a bend in sheet metal and the tonnage required to achieve that bend. It is used to determine the tonnage needed to make a particular bend on a press brake, which is a machine used to bend sheet metal.

The press brake chart is usually presented in the form of a graph, with the depth of the bend plotted on the x-axis and the tonnage required plotted on the y-axis. The chart will typically include a series of lines or curves that represent different bending angles, material thicknesses, and other factors that can affect the tonnage required.

To use a press brake chart, you first need to determine the material thickness, bend angle, and other relevant factors for your particular bending operation. You can then refer to the chart to find the tonnage required to make the bend at the desired depth. It is important to note that press brake charts are only approximate and are meant to be used as a general guide. Actual tonnage requirements can vary depending on the specific material being bent and the specific press brake being used.

## How is Calculation for Air bending Press brake machine?

Air bending is a common method of forming sheet metal using a press brake machine. In air bending, a V-shaped punch is used to bend the material over a matching V-shaped die, and the force required to bend the material is supplied by the press brake machine. The bend angle and radius produced in air bending are determined by the shape of the punch and die, the thickness and type of material being bent, and the force applied by the press brake machine.

There are several formulas that can be used to calculate the force required for air bending, as well as the resulting bend angle and radius. Some of these formulas are:

• Bend force (F): This is the force required to bend the material. It can be calculated using the following formula: F = K * T * S * R
• K: This is a factor that takes into account the material being bent, the type of press brake machine being used, and the specific bending operation being performed. K is usually provided by the manufacturer of the press brake machine or can be obtained from a press brake chart.
• T: This is the thickness of the material being bent.
• S: This is the tensile strength of the material being bent.
• R: This is the bend radius.
• Bend angle (θ): This is the angle formed by the bent material. It can be calculated using the following formula: θ = 180 * [(R – T) / R]
• R: This is the bend radius.
• T: This is the thickness of the material being bent.
• Bend radius (R): This is the radius of the bend formed in the material. It can be calculated using the following formula: R = T / (2 * sin(θ / 2))
• T: This is the thickness of the material being bent.
• θ: This is the bend angle.

It is important to note that these formulas are only approximate and are intended as a general guide. Factors such as the condition of the material, the specific press brake machine being used, and the specific bending operation being performed can all affect the actual force, angle, and radius produced in an air bending operation. As a result, it is always important to carefully consider these factors when using these formulas to calculate the results of an air bending operation. 