I wanted to make a homemade brake for bending small sheet metal
things. (I have a press). I think that the concept is straightforward,
however, I would like to know if there is any sort of a table that
tabulated bending effort per inch of the width of metal being bent,
depending on thickness.

Also, for the dies, would it be more proper to use high speed steel as
opposed to mild steel (for strength).

Thanks

i