i have read in numerous books that a stainless steel knife does not produce good sparks when used to strike a fire stick - rubbish!
i have just tested this theory with a VG10 blade and was able to produce as good a shower of sparks as with a carbon blade.
the knife used was a small folder - the Beretta Electra.
interestingly, the Electra has very sharp angles on the back of the blade - the edges are not rounded in any way. maybe the problem associated with stainless steel knives is not so much to do with the metal itself but the finish to the back of the blade....