The expansion dimension is calculated according to the center layer.
The unfolding length is related to the die R angle.
Check the size of the part after the actual folding, and then modify the blanking size.
The points on both sides of the lower die shoulder plus the dead center outer point form three points, the angle formed by these three points plus the rebound angle is the bending angle.
The rebound angle of stainless steel is about 5 degrees.
In 90 sheet metal bending, a right angle bend minus 1.7 times the material thickness is the bending angle.
For example, if the material is 1mm iron plate, the bending angle is 90 degrees, and the bending dimensions are 100 and 50 respectively, the calculation expansion method is: 100 + 50-1.7 = 148.3mm.
The calculated result is the expansion length.
This 1.7 is said to be 1.6 or 1.65 times. Yes, it can be slightly adjusted.
Because the bending dies used by each sheet metal factory are not exactly the same, there are slight errors, and they can be used without adjustment. They can also be slightly adjusted if they have high requirements.