I'd been trying to make tin alloy for a few hours (admittedly while drinking sweet, sweet booze) but burned through about 3 ceramic crucibles and failed, only ever generating "tin plates"
So I go back to NEI for the 50th time and think, "Hm, maybe I need to actually use actual tin dust for this recipe". So I grind one of the tin plates I had made only to have the mortar generate tin alloy dust -- so apparently the tin alloy plates display the name "Tin Plate" at the first line, but show "tin alloy" in the 4th line. If I hadn't activated the H+F3 feature I might have never known. Just FYI (also I'm still a little booze-o-lized so maybe I'm wrong? But I don't think so, it's been forever since I officially posted something here, and I usually check myself a few times before I post)
there is bug with naming them, try to look at contains and not on name, it should be tin alloy if you did it correctly