subject: Pressbrake Tooling: Bending And Punching Guide For Tool Settings [print this page] 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 is a method of bending sheet metal which is often used instead of press brake tooling since it produces the same end result with a smaller amount of energy. Particularly useful when working with heavy pieces of thick sheet metal, air bending is a good technique for producing complex bends in a piece of sheet metal.
Machinists and punch operators need to be aware that making accurate angular bends with this method depends on the quality and the thickness of the raw material being used. It is also important to turn the sheet slightly more than the angle intended because as you may be aware, sheet metal will spring back just a bit once it is released from the tool.
2. Coining
Coining is a bending technique which comes into play in pressbrake tooling applications. The nose of the punch is used to crush the area of the sheet metal to be bent, causing the metal to lose elasticity. One of the most important differences between coining and air bending is that the sheet metal will retain the angle of the bend once the tool has been 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
A swan neck holder or a special purpose unit can be used to make punches and notches in sheet metal. The tonnage power employed to produce these punches or notches have to be carefully regulated and kept to a maximum of 1/3 of the machine's total capacity lest damage be done to the machine. To ensure that the punch is quick and accurate, the punches must be sharpened on a regular basis.
4. Safety procedures for pressbrake tooling
There are some standard and very important safety procedures which you need to follow as you set up for a press brake tooling process. Before you begin to do anything else, ensure that the machine is turned off. The next step is to set the press brake tooling to the appropriate length for the project, followed by slightly tightening the clamp screws.
At this point, it is time to start the motor on the tool and set the regulator to approximately two tons. The idea is to ensure that the machine has just enough power to move the beam. The treadle should then be pushed down, with the bending depth control used to make sure that the top dies and Vee engage. You can then increase the tonnage to five tons while holding down the treadle and tightening the clamp screws completely; now you can begin in earnest.
