Forming a radius in a sheet having a preformed return flange is accomplished by die sets no. 101 & 102
Form fitting radius die set #103 is used primarily for small radius bends on light ga. materials.
Outside flange on a radius bend can be formed in one stroke if springback is not too great.
For radii larger than 1 1/2" set #105 is ideal, this set is also used to radius the edge of a sheet prior to a rolling operation.