[lowROLLERchevy]

Part is 1/4" steel, 1.2" wide by 12" long and needs a 4 degree bend down the middle.

Due to the narrowness of the part that pretty much limits me to a 1" V die on the bottom. Any idea what sort of tonnage Im looking at on this ? I used to know the answer but just cant recall any more. I know a full bend at these specs would be about 60T, but that also doesn't really apply to the first few degrees either.

All i remember from last time i did something like this is that the die was rated at 60T / foot and i didnt blow it up, but then again my boss put a full 350t to a 4 foot length of .125 in the same dies and that didn't blow the bottom die either.

[Pantaz]

Tonnage chart
http://www.freetechnicalcharts.com/P...nage_Chart.php

Bend calculator
http://www.pacific-press.com/bend-fo...lculator-b.php

[lowROLLERchevy]

charts and calculators are for 90* bends, I need to know the tonnage required for 4 degrees, theres a very big difference.

[Rick Neff]

The tonnage to bend metal to its yield point over a v-die is probably 80% of the tonnage required for 90 degrees. For a better description see page 7 of the Cincinnati Press Brake Capacity Guide: http://www.e-ci.com/pdf/Press-Brake-...es_PT50691.pdf
A 1" die is smaller than usually recommended to bend 1/4". Normal is 8 times material thickness or 2" but small angles can certainly be bent over a smaller die if you have the tonnage.