Derek Cohen (in Perth, Australia)
Bill, the Stewmac scraper is 1/8" thick. Mine is 3/16". I have another which is about the thickness of a Stanley blade, made from an unknown steel from a wooden spokeshave, which has Asian origins. It, too, works well. It does not appear to be about the thickness of the steel. However, it is likely that the thicker steel sections act like a heat sink.

By contrast, I have tried to make a scraper from a Stanley blade, without success. I suspect the steel was not hard enough. Years ago, the scraper that Philip Marcou made was either D2 or carbide. Probably the latter, but Philip really likes/liked D2 for blades.

Regards from Perth

Derek