Bending and punching sheet metal involves several different processes. Below are brief descriptions of a few of these processes, including information on carrying out these processes in an efficient and above all, safe manner.
1. Air Bending
Air bending refers to the process used to bend sheet metal. This process is preferred to other press brake bending techniques that can be used to achieve the same objective because it requires less energy to effect the bend especially where thick and heavy sheet metal is involved. Further, air bending can be used to achieve diverse and complex angular bends on the sheet metal.
That said, the accuracy of the angular bends has a lot to do with the quality and thickness of the sheet metal used. It is important to note that when using air bending, you should turn the sheet slightly beyond the desired angle of the bend. This is because sheet metal will usually marginally spring back after the sheet is released.
2. Coining
Coining is another bending process used in press brake bending. In this process, the punch’s nose crushes the sheet metal within the bending radius so that the sheet metal loses its elasticity. Thus, unlike air bending, the angle at which the sheet is bent using coining is retained even after the tool is disengaged.
For this reason, coining can thus be used to achieve a more precise angle bend. However, the drawback with this particular process is that you require a high tonnage to realize the bend.
3. Punching and notching for press brake tooling
Notches and punches can be made in sheet metal with either a swan neck holder or specially designed units. The tonnage used while making the punch must be carefully controlled to ensure that it remains at 1/3 or less of the tool’s total capacity in order to prevent damage to the machine. When punching and notching, the quality of the punch is paramount to determining the speed and accuracy of the end result; for this reason, it is very important to sharpen the punches regularly.
4. Press brake tooling safety
There are various safety procedures that you should adhere to when setting press brake tooling. First, always ensure the machine is turned off before you begin working. Fit the press brake tooling to the length required and slightly tighten the tool’s clamp screws.
Start the motor and adjust the regulator to about 2 tons so as to make certain that there is only enough power to move the beam. Push the treadle downwards and use the bending depth control so that the top dies engage the Vee. Increase the power tonnage from 2 to 5 tons as you hold the foot treadle down and then tighten the tool clamp screws fully and then you are ready to go.
W Fearnehough is an established Press Brake Tooling Manufacturer located in the East Rand, South Africa. To find out more information on pressbrake tooling and its technology, go to Quality Pressbrake Tooling This article, An Introduction To Pressbrake Tooling Bending And Punching is released under a creative commons attribution licence.