Your Leek uses a stainless steel known as 440A; not the world's greatest steel but still not all that bad for casual, everyday use. The SOG uses AUS-8 stainless which is a Japanese modified version of 440B stainless. The modification includes adding a touch of Vanadium which acts as a hardener and grain refiner(smaller grains mean stronger steel). It's a better steel than 440A or standard 440B, since it will hold an edge longer, but is still not hard to sharpen. The BUCK uses a steel they call 420HC which is not a real name(they made it up......there is a 420 steel, but not 420HC). There are about 10 kinds of 420 steel, some of which don't really qualify as steel due to their low carbon content, and others which barely qualify as steel. 420 is popular with knife manufacturers because it's available in hugh rolls/sheets; therefore cheap to buy. It's easy to stamp and shape; therefore cheap to manufacture blades with. It's junk. It's hard to tell which version the manufacturer is sticking you with, but none of them are really worth a hill of beans except in a couple of areas,i.e. dive knives and filet knives come to mind. I've a couple of jack knives with that steel that were given to me as gifts, and they can't hold an edge at all, except when used in the lightest tasks. The SOG gets my vote just based on the steel. Never used one so can't say more than that.
