No steel knife of any type can even begin to approach that sort of sharpness. Learn how to knap a flint for maximum sharpness. It makes a big difference in how strong a string of sparks you can toss from the steel. Some of the best flints I ve ever had have been flakes and spalls left around after someone demonstrated arrowhead making. They re small and exceedingly sharp.
Rule of thumb is that the darker the piece of flint, the harder it is.
And the harder the piece of flint, the lower it dulls. But I ve seen some awfully light colored flints throw some very impressive sparks. So I give sharpness the nod over the hardness of the flint. If you can find it, get a chunk of red jasper. Some parts of the country it is easy to come by, and others quite difficult.