You might have to be a bit more specific as to what you are looking for. It sounds like you are trying to stacking multiple pieces of sheet metal and want to know what the minimum bend radius is for a flange. Typically, the allowable bend radius depends on two things, one - the ability of your fabricator, and two - the material you are using. For example, an Aluminum 6061-T6 alloy at 1/8" thickness, the bend radius is between 0.188" (1.5t) and 0.375" (3t).
