If the legs of a profile are bent step-by-step in consecutive sets of rolls, the edges travel a longer way than the web of the profile. This causes a strain and a stress in the edges. If this process is limited to the elastic area of the material, the strain and stretching will return to the original length again, as the profile leaves the stand. In the other case, if the stress of edge has exceeded the yield stress between two bending steps, this will cause a remaining strain in the material causing problems like bows or ripples or other unwanted deformation of the profile. The relative stress related to the yield stress is calculated and displayed in a separate window. By this, the designer can check if the safe load of the band edges is kept while bending.

The calculation of stress of band edge is the first step of the three steps quality management concept. Compared with step 2 (PSA - Profile Stress Analysis) and step 3 (FEA - Finite Element Analysis) the calculation of stress of band edge enables the designer to estimate the stress very quickly. Most profiles have highest stress at the edges.

More: Quality Management in Rollform Design