Urban myth, hmm? Sorry atoz, I was given my first Doans over 20 years ago, and I've been using them ever since. I get about half, two-thirds as many sparks with a stainless scraper as I do carbon- same angle, same pressure, same scraper thickness (near enough- not enough for the eye to see).

There was also an evaluation of scraper materials done by a member about a year ago or so, he found a super high carbon tool steel did the very best. High chromium, low carbon steel did the worst.

Stainless sucks on ferro rods. Beginning and end of story.