Description says "set a target quality" I see no option for that.
I'm using King Jo's vehicle mods and the quality bonus for the gas cans are better vehicle acceleration.
With 1 quality-1 normal-quality module (+1% quality total) it ate through about 150 gas cans without giving me one uncommon, but worked with iron plates fine 1:100.
I think it may be because it has a stack size of 4, and there are only 20 inventory slots, so I can only add 80% of an uncommon to the inventory at once?