How to choose correct bending V size?

Many users do not know how to choose press brake dies, especially the notch plagues problems distract them.

Figure 1  V size and plate thickness

The recognized bending force calculation formula of notch used in the market is V=8T, but this formula has its drawbacks. It is not suitable for bending workpieces with high precision requirements and small workpieces with radian requirements.

Figure2  Relationship of thickness and V size

According to BLMA's conclusion from the data provided by a large number of sheet metal processing from our users, top select thin plate processing molds, the formula of V=6T fits for plates below 3mm. For plates between 3 to 8mm, V=8T can be used for high requirement customers. For plates more than 8mm thickness,  V=12T can be used if the customer does not require high accuracy and radian. In this way, a bending machine with a smaller tonnage can be selected, and thus to save costs. Refer to Figure 2 above.

The biggest disadvantage of using big V notch is that the quite bigger plate radius than the normal. Hence, users have to be cautious in choosing big V size moulds if only require small arc of workpieces. Details refer to Figure3 below.

Figure 3  Bending arc

Generally, for precise bending workpieces, customers will choose the same core lower mold or single V mold. However, for those customers who have limited budget, multiple V moulds might be a good choice for them. BLMA has over 20 years experience in press brake moulds design and production, and is possible to provide more reasonable suggestions and multiple choices based on customers’ point of view.

Figure 4  Different type of press brake moulds