When engineers need to make curved or bent pieces of sheet metal, they use company-written tables, rules of thumb, and guesstimates to determine the length of straight stock needed for bending ...

Estimating Sheet-metal bend allowances using equations. A reader recently requested a copy of this feature from our archives. You may also find it valuable. Click the image to view the full pdf ...

The project came about simply because [Bob] needed to bend 42″ sections of flashing, and couldn’t find a decent deal on a sheet metal brake above 36″ wide.