Strangley, the striker that I have had the best result with is an actual bit of flint. It was the only thing I had at hand and it worked great. The advantage of it over a hacksaw blade is that it doesn't wear down the blade as fast. This is because, as our archaeology teacher keeps telling us "flint can be struck sharper than a modern razor blade" <img src="images/graemlins/smirk.gif" alt="" />