Steel Type and Blade Thickness

[superflyafro]

What's a better steel 440C or AUS-8?

Is 3/16" a nice thickness for a knife?

 

[rifon2]

With all else being equal (heat treat, etc.); AUS8 is more or less equivalent to 440B.
One step "below" 440C.

Check out the steel guide here: http://www.agrussell.com/Steel_Guide/a/73/

And as for blade width, it depends on what type of cutting you'll be doing with the blade.
But 3/16" is a good general purpose thickness for a fixed blade knife.