There are two methods that press brakes can bend steel. The first, or bottom bending, is when the ram presses metal to the bottom. Bottom bending can produce precise bends and is less dependent on the press brake. The problem is that each tool is designed for a specific type of bend. You will need to purchase a brand new tool for each angle. Air bending creates an air pocket between the die's bottom and the ram. This allows the operator flexibility in accommodating any spring back provided by the material. These types are only necessary to be replaced if the material is too thick. The drawback of air bending is its inability to accurately bend the material. This means that the ram will need to be changed accordingly.
Hydraulic press brakes apply pressure via hydraulics to force the ram down, instead of relying solely on mechanics. They may have more than one cylinder and give the operator more precise control over the bend. The result is a highly accurate and customizable bend. Like mechanical press brakes, hydraulic press brakes do have some specific disadvantages. Primarily, they cannot exceed the range of their rated tonnage. If your project requires flexibility, mechanical press brakes may be preferred.
