I have made blades using 3/32" steel, but no thinner than that. It is harder to work with than thicker steel (for me). I still hollowgrind it and end up with a very thin blade that can get wicked sharp.
But the thinner the grind, the more flexible the blade.
We are basically talking about kitchen knives here, steak and paring knives. Also filet knives.
Hunting knives, in my opinion, need to be a tad thicker than 3/32.
Dan