It is my understanding that the USAF "survival" knive has what pass for saw teeth on the back so that it can be used to saw thru plexiglas or the aluminum skin of an aircraft. I never got a chance to use mine on those materials, but just for the heck of it I sawed a 2x4 in half with it, and it worked pretty good for that. I did snap the tip off while trying to husk a coconut tho...<br><br>There are many knives available with really effective saw teeth, you might consider something along those lines...