KOA are a great brand. They use great steel in my experience, the ones i have encountered were D2 tool steel, which performs wonderfully. I know that they are using other steels in their line as well. I cant tell you which models use what steel, but their printed catalog does. If you can find someone who sells them in the area take a look. If not try contacting them on their website and request info about the blade steels, and any other info you would like to know. Hope this helps.
J
http://www.knivesofalaska.com/contact.aspx