Sheet Metal Bending [see Machinery's Handbook 29th Ed. p. 1347]

The inside bend radius of sheet metal parts must be within defined limits.
As a rule, minimum inside bend radius should be equal to material thickness. When the radius is less than recommended, this can cause material flow problems in soft material and fracturing in hard material.
The maximum inside bend radius represents the limit at which permanent plastic deformation in the outer fibers of the bend workpiece is still achievable.



R_{max} = \frac{TE}{2(YS)}R_{min} = T\left(\frac{50}{r}-1\right)F = \frac{LT^{2} (UTS)}{W}

Typical sheet metal materials are: Brass, Copper, Steel, and Aluminum.
Some material properties can be found in Table 1

Sheet metal thickness (T): in
Sheet metal length (L): in
Die opening (W): in
Yield Strength (YS): ksi
Elastic Modulus (E): ksi
Ultimate Strength (UTS): ksi
Percent Reduction (r): %   

--

Copyright © | Estiven R. Sierra