Cold Steel website's FAQ covers edge angles. Basically for the big blades, it's 40 inclusive. For the small blades, do 30 inclusive. That's if you're using a sharpening system, like the Spyderco triangle sharpmaker. If just using a stone, you can't really go wrong sharpening at half of a right triangle for most knives. (45 degrees divided by 2 = 22 1/2 degrees) For a small folder, you might want to lay the knife just a bit flatter.