Bends For the ease of manufacturing, multiple bends on the same plane should occur in the same direction. Avoid large sheet metal parts with small bent flanges. In low carbon steel sheet metal, the minimum radius of a bend should be onehalf the material thickness or 0.80 mm (0.03 inch), whichever is larger. Bends specified as angles may be toleranced at plus or minus one-half degree at a location adjacent to the bends. Curls The minimum radius is two times the material thickness with an opening to a minimum of one material thickness. The minimum distance between a curl and the edge of a hole is the radius of the curl plus the material thickness. The minimum distance a curl should be from an internal bend is six times the material thickness plus the radius of the curl. The minimum distance a curl should be from an external bend is nine times the material thickness plus the radius of the curl. Dimples The maximum diameter should be six times the material thickness, and a maximum depth of one-half the inside diameter. The minimum distance that a dimple should be from a hole is three times the material thickness plus the radius of the dimple. The minimum distance that a dimple should be from the edge is four times the material thickness plus the inside radius of the dimple.