When calculating the unfolded length of sheet metal . And when 90 degree bending sheet metal ,or when doing cad sheet metal unfolding, we always hope to improve efficiency.
The simpler the calculation, the better. In fact, if not require accurate sheet metal errors , a simple method can use to calculate the bending coefficient.
The simplest calculation method of bending coefficient is the empirical formula of 90 degree bending coefficient. It is 1.7 times the material thickness calculation method.
Used in 90 sheet metal bending processing, a right-angle bend minus 1.7 times the material thickness.
For example: the material is 1mm iron plate, the bending angle is 90 degrees.
And the bending dimensions are 100 and 50 respectively. Then the calculation method for expansion is: 100+50-1.7=148.3mm.
The calculated length is the expanded length. Some people say that 1.7 is 1.6 or 1.65 times. Yes, it can adjust slightly .
Because the bending molds by each sheet metal factory are not exactly the same.
There are slight errors, and it can use without adjustment, and it can adjust slightly if the requirements are high.
Sheet metal bending is not only 90-degree bending, but also non-90-degree bending. Here is a special angle, and you can use a simple method to calculate the bending coefficient.
When the sheet metal bending angle is 135 degrees, the bending coefficient can be reduced by 0.5 times the material thickness. For example: the material is 1mm iron plate, the bending angle is 135 degrees, and the bending dimensions are 100 and 50 respectively, then the calculation method for expansion is: 100+50-0.5=149.5mm.
Other sheet metal thicknesses can also calculate by this method. Only applicable to 135 degrees, other angles are not available.
There is also a special angle bending in sheet metal bending, which is sheet metal frill, also called dead edge, which can calculate in a simple way. The bending factor is equal to 0.4 times the sheet metal thickness.
For example: the material is 1mm iron plate, the bending is the dead edge, and the bending size is 100 and 10 respectively, then the calculation method is: 100+10-0.4=109.6mm.
This calculation is an empirical formula and it is very accurate, and some sheet metal factories may have differences due to different equipment.