Not to hijack your link, but what about steel used for razors in the mid 19th century? There are Soligen and Sheffield and probably others. Were all razors marked "Sheffield" or "Soligen" made from the same metal? I find it a little hard to believe that a razor manufacturer back then would have a special steel made just for different grades of razors. Or different razor manufacturers would have special steel made just for themselves. Which leads to my further question. Was a Wade and Butcher Sheffield steel razor made of the same steel as, say, a Greaves or an Allen?