There are some sheet metal components which are designed in the bed way bend. The bend radii are stated as sharp or only a small radius is allowed. When we spotted this error, we used to feed back to the component designer asking for a change in design or to enlarge the bend radius.

There are differences between good way and bad way bends. In general, the good way bend is the axis of bend perpendicular to the Grain flow of the sheet metal, the bed way is the bending axis parallel to the rolling direction. A good way bend, the sheet metal can be formed or bent with sharp or small bend radius without having any crack or rupture at the bent edge, but the bad way requires a larger bend radius in order to avoid crack at the bent edge.

The minimum allowable bend radius difference from different material type, as it is just a general guideline, the softer and thinner the material, the smaller the allowable bend radius compare to the harder and thicker material.

A general guideline, a cold roll steel which under 1.5mm thick, the minimum allowable radius is equal to the thickness of the material for 90 degree bend, material from 1.5mm-2.0 mm thick, the minimum allowable bend radius will be ranging from 1.5-2.5 time the material thickness.