There should have bending radius for sheet metal bending, bending radius should not be too large or too small, it should be chosen appropriately. Nonetheless, the answers are there, waiting for you to find them.' This should include data from your material supplier, whether you are bending with or against the grain, as well as information specific to the application. Finding the true minimum bend radius for steel or aluminum plate requires a little research. So in this case, the minimum inside bend radius is 2 times the material thickness. Now, multiply that answer by the plate thickness. Next, subtract 1 from that answer: 5 – 1 = 4. If the steel has a tensile reduction value of 10 percent, divide 50 by that value: 50/10 = 5. There’s a rule of thumb to determine a steel’s minimum bend radius, and this generally works for aluminum too: Divide 50 by the material’s tensile reduction percentage as specified by your supplier.