i have used skill saw blades for knife making
what i do is
after cutting my shape from the blade,cleaning up all edges,get the bevel done
get the cutting edge to vey near a sharpened edge
then i fill my old wber grill full of charcoal and get them coals cherry red
stick the blade in ther for aboot an hour or so,you want it cherry red hot so a magnent wont stick
then quench it in a pan of vegie oil that has been preheated to aboot 135*-150*,leave it in there untill it quits boiling the oil
note:when placing in pan of oil, slowly and carefully place in as if you were sticking the blade into a knife block or whatever,you know from tip to handle slowly untill submerged.this will help prevent warping of the blade which WILL happen if you just drop it in
then quickly,but carefully wipe it down and stick it on a preheated pan in a preheated oven set at 350* for an hour
then shut the oven off and just let it cool all the way down before removing from the oven
you will have some black carbon like material to clean off the blade
but it will hold a nice edge and not rust easily either
atleast it work that way for me
not saying this is the right way or only way or best way
this is just how i do it and it seems to work for me