Some recipes can't be replaced?

I've done the trick to remove a bunch of recipes from the game (Recreating the recipes exactly but making the product an air block)
But for some reason not all the recipes work.
I've tried to remove stone tools, iron tools, and iron armor, but for stone tools it won't let me remove swords and shovels, and for iron tools it only lets me remove axes and shears.
I'm really confused, and I've tested for hours to make sure I wasn't making any weird mistakes.

Any ideas?