Metal Bending is a process that involves the shaping of metals to a predetermined shape by applying force to it. This then causes such metal to bend at an angle to form a particular shape. In doing this, a press brake tool is usually employed to bend the sheet metal.
There are three basic types of metal bending: Air bending, Bottom Bending/Bottoming, and Coining. These typifications are based on the relationship of the end tool’s position to the thickness of the material.
This is the most preferred type of metal bending due to its benefits – such as less need for the punch tip to be pushed past the surface of the metal and less weight required for bending.
Air bending is the process of forming materials by pressing a punch into the material, thereby forcing it into a bottom V-die to be mounted on the press. This enables the distance between the punch and the sidewall of the V to be greater than the material thickness.
Unlike the other types, the least amount of contact with the material is usually made in air bending, as the equipment touches the material only at three points i.e., at the punch, the tip, and the die shoulders. While its disadvantages are the difficulties in providing accuracy of the stroke depth and the difficulty of the sheet in maintaining contact with the dies.
The distinction between air bending and coining is that, unlike the former, there is a difference in radius between the two. While, unlike the latter, the punch and the die do not make full contact with the material, and there is usually insufficient tonnage to make an imprint into the material.
The advantages of bottoming include better accuracy and fewer spring-backs, while the disadvantages are that a different tool is usually needed for each bend angle, sheet thickness, and material.
Here, the material is forced by the top tool into the bottom die with 5 to 30 times the force of air bending. Therefore, causing permanent deformation through the sheet. Note that coining may produce an inside radius as low as 0.4 T, with a 5 T width of the V opening. While coining can attain high precision, however, higher costs signal that it is not often used. Additionally, more tonnage is required on this type of bending than in the others.
The advantages of coining are that, to produce outstanding results, accuracy is essential, and with the coining method, this can be achieved. Also, the difficulties with spring-back are extinguished with coining.
We offer a large and diverse steel & aluminum inventory coupled with an extensive array of in house metal processing equipment that allows us to service customers on an unparalleled level. For questions or information on our products and services call us today at 978-658-1121 or contact us directly on our site.