A press brake is one of the most versatile and reliable tools in sheet metal manufacturing, but when it comes to tight-tolerance precision work and maintaining consistency, it’s all in the tooling. Press brake tooling varies to incorporate L-shape, R-shape, U-shape and Z-shape bending. When running into issues with your press brake, one of the first steps is to check if there are issues with the die or punch tooling. Remember, the die is the only aspect of the press brake that touches the sheet metal during the bending process.
Many modern press brakes are self-aligning with fast clamps or hydraulic systems in place to allow your top and bottom die to be clamped neatly into place, every time. However, older press brakes with multi-V blocks that need manual alignment by turning front and rear handles are still reliable machines used to bend sheet metal today. For jobs that require precision, manually setting up the correct bend angles can be time-consuming, so it is best to recognise early when the tooling is incorrect or misaligned. If you suspect your tooling is not aligning accurately or not performing well, here are some simple checks that may solve the issue.
Check cleanliness of tooling
Before using the press brake, ensure the tooling appears spotless. If there is dust or debris from previous metal materials on the tooling or under the die, you risk denting the tooling or the metal sheet. Before manually aligning the V of the die in the press brake, clean all sides of the tooling and the bed with WD 40. This will prevent the metallic flakes and debris from being compressed into the tooling or the seating, causing gradual changes to the press brake tooling height that will impact your sheet metal bends and reduce accuracy.
Tooling wear and tear
If during the cleaning it is revealed that there is wear and tear on your press tooling, it is time for it to be replaced. Dies will deteriorate over time, and even slightly worn tooling will produce inaccurate and inconsistent bends for an overall poor result. Upgrading older tooling with faults will be much cheaper in the long run than the wastage of metal and time.
You can inspect for wear by measuring from the nose to shoulder on the punches and from shoulder to shoulder on the dies. To properly maintain your press brake tooling after usage, remember to store the die in a cabinet with accurately displayed markings, clean them regularly and apply anti-rust oil to avoid reducing their precision over time.
Confirm appropriate tooling in use
If the press brake isn’t performing as well as you had hoped, it may be due to the usage of incorrect or incompatible tooling. There are many tooling types and choosing the right upper die and lower die is dependent on many factors including sheet metal hardness, thickness and length. Tooling selection is also impacted by the bending method used. Generally, the slot width of the lower die needs to account for the width of the upper die and the length should be longer than the workpiece.
A wider lower die slot is also necessary when using sheet metal that has a higher density or strength. Always confirm that the tooling in place is appropriate for your material and desired shape by noting the punch angle, die angle and die opening. If you don’t check your tooling before attempting to bend sheet metal you risk damaging your tooling or exceeding the safety limits of the press brake.
Tooling seating check
If your die seems correct and in shape, take a moment to check the seating of the upper and lower tooling. When using hydraulic clamping, the tooling will always be accurately seated. With older models, an operator will need to ensure the tools are correctly seated by bringing down the ram and applying light tonnage before tightening them. After placing the tooling into the top and bottom gauges, move your machine into slow speed to check alignment.
If your press brake has front and rear handles, the operator will have to adjust them carefully while looking down the centre. It is also important to confirm that the workpiece is steady against the back gauge to prevent minor sheet metal movement. If you’ve checked the top and bottom tooling and confirmed the alignment is correct but your press brake is still not cooperating, it may be time for a maintenance check-up of the press brake machinery.
In need of new tooling?
For assistance in selecting the right press brake model for your metal fabrication needs, or to expand your tool library, get in touch by calling us on 03 9794 6675 or filling out our online contact form.