Why is your bending accuracy always a little off? Master these tips!

In the field of metal processing, bending accuracy is one of the key indicators to measure product quality. Many practitioners often encounter this dilemma: even though the operating procedures appear correct, the resulting workpiece accuracy may be slightly off, affecting subsequent assembly or product quality. Today, let’s talk about the things that affect bending accuracy and share some practical tips to help you solve this problem.

1. Material factors: choosing the right material is the basis

The properties of the material have a direct impact on the bending accuracy. Metals of different materials have different properties such as ductility and tensile strength. For example, for stainless steel and ordinary carbon steel of the same thickness, the springback rate of stainless steel is relatively higher. If stainless steel is processed according to the bending parameters of carbon steel, the accuracy will naturally deviate.

Therefore, before bending, you must fully understand the characteristics of the material. For materials with high springback rates, the bending angle can be adjusted appropriately to reserve space for springback. At the same time, ensure that the material surface is flat and free of scratches or impurities. These seemingly minor defects can lead to uneven stress distribution during the bending process, thereby affecting accuracy.

2. Equipment debugging: details determine success or failure

The debugging of the bending machine is an important part of ensuring accuracy. Many accuracy problems are caused by inadequate equipment debugging.

(1) Mold installation and alignment

The mold is the component that comes into direct contact with the workpiece for bending, so precise alignment of its installation is crucial. If there is an offset between the upper and lower dies, even a very small deviation, after multiple bending cycles, the accumulated error will greatly reduce the accuracy. When installing the mold, carefully align it using specialized tools to ensure that the mold's centerline aligns with the press brake's worktable centerline. The mold surface must be kept clean to prevent foreign matter from causing a loose fit.

(2) Pressure and speed settings

Improperly setting the pressure and speed parameters of the press brake can also affect accuracy. Too little pressure prevents the material from being fully bent, leading to springback. Too much pressure can cause excessive deformation and even damage the mold. In terms of speed, too fast a bending speed will cause the material to generate greater inertia during the bending process, affecting the accuracy of the bending angle. The appropriate combination of pressure and speed parameters should be found through multiple tests based on factors such as material thickness, material, and bending angle.

(3) Selection of the lower die V-mouth and calibration of the slider parallelism
The slider gap and lower die V-mouth selection of the bending machine will also affect the accuracy. For example, if the V-gap is too small, the sheet metal can be easily crushed and the angle can be "over-bent" due to excessive force. If it is too large, the sheet metal will not fit properly and the angle will rebound beyond the specified value after bending. There is also the parallelism of the slider. If it has not been calibrated for a long time, the gap on the left is 1mm and the gap on the right is 1.2mm. The left and right angles of the folded workpiece can differ by more than 1°. It may not be obvious to the naked eye, but you will find that the holes do not match during assembly.

3. Operation skills: Standard operation is the key

The operator's operating techniques and habits will also affect the bending accuracy.

(1) Workpiece positioning must be accurate

When placing the workpiece for bending, it is necessary to ensure that the workpiece is positioned accurately. The workpiece can be firmly fixed in the correct position with the help of the positioning device on the bending machine or by using auxiliary fixtures to prevent the workpiece from shifting during the bending process. For workpieces with complex shapes, it is even more important to carefully determine the positioning points to ensure that the benchmarks for each bend are consistent.

(2) Order of step-by-step bending

When the workpiece needs to be bent multiple times, the order of bending is very important. An incorrect bending sequence can cause interference from previously bent sections during subsequent bending, affecting accuracy. Generally speaking, the principle of working from the outside in, from simple to complex, should be followed: first complete the sections that have the least impact on subsequent bending, then gradually proceed to more complex bending operations.

4. Daily maintenance: Equipment maintenance is essential

Daily maintenance of the bending machine is the premise for ensuring its long-term stable and high-precision operation. The equipment should be cleaned and lubricated regularly, and the wear of each component should be checked, such as whether the cutting edge of the mold is worn, whether the transmission components are loose, etc. Timely replacement of severely worn parts and tightening of loose parts can effectively avoid precision problems caused by equipment failure or component aging.

In short, to improve bending accuracy, it is necessary to comprehensively consider multiple aspects, including materials, equipment debugging, operating skills, and daily maintenance. Paying attention to every detail and strictly following the specifications for operating and maintaining the equipment can keep the bending accuracy at an ideal state and produce high-quality metal processing products.