The unfolded size is calculated according to the central layer, and the unfolded length is related to the R angle of the model on the flange. Check the part size after actual folding, and this is regular, then modify the unloading size. There are points on both sides of the model and points under the knife. The angle formed by the three points plus the rebound angle is the bending angle. The rebound angle of stainless steel is about 5 degrees.
In the 90-sheet metal bending process, a right-angle bend minus 1.7 times the material thickness. For example, if the material is a 1mm iron plate, the bending angle is 90 degrees, and the bending dimensions are 100 and 50, respectively, then the calculation and expansion method is: 100 + 50-1.7 = 148.3mm. It is the expansion length that is calculated. For 1.7 times, some people say it is 1.6 or 1.65 times. Yes, it can be adjusted slightly. Because the bending mold used by each sheet metal factory is not the same, there is a slight error, it can be used without adjustment, and it can be adjusted slightly if the requirements are high. Sheet metal components are widely used in the aerospace and electronics industries, and high precision is the basic requirement of the final product. In precision components, the calculation of the bending allowance is very important to reach the final size of the sheet metal development length.
When the bending angle of the sheet metal is 135 degrees, the bending factor can be reduced by 0.5 times the material thickness. For example: the material is a 1mm iron plate, the bending angle is 135 degrees, and the bending dimensions are 100 and 50, respectively, then the calculation and expansion method is: 100 + 50-0.5 = 149.5mm. The thickness of other sheet metal can also be calculated by this method. This only applies to 135 degrees, and other angles are not available.